Questions and answers about common sense in grade two.

1. Second grade encyclopedia common sense and answers Volume I

The second grade encyclopedia common sense and answers Volume 1 1. What scientific knowledge did you learn in the second grade last semester?

1. Appendix+Appendix = sum coefficient * coefficient = product

Sum-addendum = addendum product/coefficient = coefficient

Minus-Minus = Differential Divider/Divider = Quotient

Negative difference = negative dividend = divisor

Subtraction+difference = dividend * quotient = dividend

2. separator >; Remainder divisor * quotient+remainder = dividend divisor * quotient = dividend-remainder

3. A figure composed of two rays from a point is called an angle.

A corner has a vertex and two straight sides.

A triangular ruler has three angles, one of which is a right angle.

4. Features of Cubes and Cubes

* * * Similarity: Cubes and cuboids have 6 faces, 12 sides and 8 vertices.

Difference: All six sides of a cube are squares.

A cuboid has six sides that are all rectangular, or two opposite sides that are square.

The 12 sides of a cube are all equal.

The 12 edges of a cuboid are not all equal. The 12 edges of a cuboid can be divided into three groups, and each group has four equal-length edges.

In two groups, one group has four equal-length sides and the other group has eight equal-length sides.

Relationship: Cubes are special cuboids.

5. It takes at least 8 small cubes to form a big cube.

6. The characteristics of squares and rectangles

* * * Similarity: Both a square and a rectangle have four sides, four right angles, and the opposite sides are equal.

Difference: Four sides of a square are equal, or adjacent sides are equal.

The opposite sides of a rectangle are equal.

Relationship: Square is a special rectangle.

7. It takes at least four small squares to form a big square.

8. One

Four times the square number or the square number.

The sum of consecutive odd numbers starting from 1 is a square number.

9. Multiply one factor by several and divide another factor by several, and the product remains unchanged.

10. Multiply any number with 10, just add 1 zero at the end of this number.

1 1. Multiply any number by 0, and the product is 0.

Divide 0 by any number that is not equal to 0, and the quotient is 0, so 0 cannot be divided.

2. Second-year extracurricular required reading exercises and answers.

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Second grade, volume one, extracurricular required reading exercises (1)

First, multiple choice questions

1. Grandma Hua lives in ()

A small mountain village in a small house by the sea

2. Flowers planted by my mother-in-law ()

Jia Bai Li yi Lu

3. Hua is ()' s mother-in-law

A loves life and is willing to give. B likes small animals.

4. The cat that lived 6.5438+00000 times finally became (), and it began to like itself.

A wild cat, king B's cat. Cats that have lived 654.38+00000 times like () more than themselves.

A white cat and kitten b fresh fish

6. A cat that has lived 654.38+00,000 times reminds me that this is a need ().

A. play b love

7. In Puss in Boots, the troll becomes () eaten by the cat?

A lion and a mouse.

8. In Cat in Boots, the cat's boots were given by ().

Master a and king b

9. In The Ducks Become Superman, () made a kite.

Duck duck duck goat Kurt

10. In "Ducks as Captain", () took Kurt the goat's gasoline and whipped a duck, frog B.

1 1. A Fu, A Lu and A Shou are ()

Jia Shang yi farmer

12. Villagers () strangers

A believes B doesn't.

13. When everyone gives with an open mind, the next person will give ()

A little, B much.

14. The gift that the monk brought to the villagers was ()

A share happy b shitou soup

15. In "The Eagle Unwilling to Fly", the eagle grew up with ().

A hen and a duck

2. The judge judges whether it is right or wrong. Put "√" in brackets for the right and "*" for the wrong.

1. Three monks knocked on the door of the second house, and someone answered the door at once. (9.A 10。 A 1 1。 A 12。 B 13。 B 14。 A 15。 AA8.A

3. What did you learn in the second grade of primary school this semester?

This semester is coming to an end. Let me tell you something about my harvest this semester!

In Chinese, I know many new words and write many new words. I also met many famous people, namely: Zhang Heng, Edison, Ron Wan Zhi, Archer ... They taught me a truth: be willing to use your head, think more and help others more. I also know many famous sayings: knowledge is our wings to fly to the sky; Thinking can form a bridge and lead us to new knowledge. ...

In mathematics, my calculation has made great progress compared with last semester. I also learned division in tables, numbers within ten thousand, grams and kilograms, figures, finding rules and solving problems. My favorite units are grams and kilograms because I know the weight of different things from them.

Through physical education class and body dance classes, I learned how to prepare for flag-raising and do morning exercises, so that my body can get exercise and be healthier.

In addition to the gains in learning, I also know a lot of truth. For example, we should use our brains, listen to other people's opinions, observe things carefully and be caring. The second grade passed in a blink of an eye, and I was already a primary school student in the third grade in the next study. I will continue to work hard and gain more knowledge and truth.

4. Astronomical knowledge that should be known in the second grade of primary school

Some celestial bodies in black holes are so massive that their gravity is so strong that nothing can escape from them, even light.

Without light returning, the eyes can't see the object, so it is called a "black hole". People on the earth of the zodiac look at the apparent path of the sun among the stars in a year, that is, the great circle where the earth's orbital plane intersects the celestial sphere forms an angle of 23 degrees and 26 minutes with the celestial equator, and intersects with vernal equinox and vernal equinox.

The two points on the celestial sphere of the yellow pole are 90 degrees away from the ecliptic angle, and those close to the north celestial pole are called "North Yellow Pole". The angular distance between the ecliptic pole and the celestial pole is equal to the ecliptic angle.

The North Yellow Pole is located at the center of the connecting line between Tianlong and the two stars. Zodiac: A strip on the celestial sphere with 8 degrees (* * * width 16 degrees) on each side of the ecliptic.

The orbits of the sun, the moon and the main planets are all on the ecliptic. To show the position of the sun on the ecliptic.

Divide the zodiac into twelve segments, which is called "Zodiac". From the vernal equinox, they are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces.

In the past, the zodiac and the zodiac were the same. With the vernal equinox moving westward, the vernal equinox in Aries has moved to Pisces two thousand years ago, and its name is no longer consistent with the constellation.

The three walls include Ziwei Garden, Taiwei Garden and Tianshi Garden. Purple element includes the sky area near the north celestial pole, which is roughly equivalent to the area of arch star; Taiwei Courtyard contains some constellations such as Maiden, Houfa and Lion. Tianshi source includes snake man, five immortals, giant snake, skyhawk and other constellations.

Twenty-eight lodgings are divided into seven lodgings in the east, seven lodgings in the west, seven lodgings in the south and seven lodgings in the north. Twenty-eight hotels are also called twenty-eight stars or twenty-eight houses.

At first, the ancients chose 28 stars to compare the movements of the sun, the moon, gold, wood, water, fire and earth as observation marks. The meaning of "lodge" is similar to the "palace" of the zodiac, indicating the position of the sun, moon and five stars.

In the Tang Dynasty, Twenty-eight Hostels became the main body of the twenty-eight celestial bodies, and these celestial bodies were still named after Twenty-eight Hostels. Different from Sanyuan, as a celestial body, Twenty-eight Hostels are mainly used to divide the ownership of star officials. The 28 huts start from Kakuk and are arranged from west to east, in the same direction as the sun and the moon.

East seven houses, namely Jiao, Kang, Emperor, Fang, Xin, Wei and Yi; North Seven Nights: Dou, Niu (Petunia), Female (bearded female), Virtual, Dangerous, House (Barracks), Wall (East Wall), West Seven Nights: Kui, Lou, Wei, Chang, Bi, Gou, Shennan Seven Nights Well (Cave Well), Ghost (Yugui) and Willow. In addition, there are some star officials who are closely related to these star officials, such as tomb, detached palace, ear, chop, graupel, corpse accumulation, right jurisdiction, left jurisdiction, Changsha, shrine and so on. , belonging to room, danger, room, completion and participation respectively.

In the Tang Dynasty, there were 183 stars in 28 places, including auxiliary officials or auxiliary stars. Cosmic velocity refers to the initial velocity necessary for launching artificial celestial bodies from the earth into the universe.

The first cosmic speed People call the speed of 7.9 kilometers per second "the first cosmic speed", which is also called "circumpolar speed". Below this speed, the object will return to earth under the action of gravity. Second cosmic speed If we increase the speed to 1 1.2 km/s, this artificial satellite can travel to the interplanetary space of the solar system without being affected by the gravity of the earth.

People call the speed of 1 1.2km/s the "second cosmic speed" third cosmic velocity. If the satellite is to fly out of the solar system and go to other planets, the speed must be increased to 16.7km/s, which is the so-called "third cosmic velocity". Because the number of days in the tropic year is not an integer, the number of days in a year is different from that in a leap year, some are 365 days and some are 366 days.

A year with 366 days is called leap year, and a year with 365 days is called average year. February in leap year is longer than average 1 day, and so are other months.

Generally speaking, a year divisible by 4 is a leap year. If the year is an integer of 100, the year divisible by 400 is a leap year. The lunar calendar of leap month and the solar calendar contain different days in a year, about 365 days in the solar calendar and 354 days in the lunar calendar.

In order to make the number of days in a year the same, one month is added in some years of the lunar calendar, and the added month is called "leap month". Because the Gregorian calendar year is only about 1 1 day older than the lunar calendar, it is impossible to add leap months every year. About 19 has seven leap months.

The time for the earth to orbit the sun once in the tropic year is called tropic year. The tropical year is 365 days, 5 hours, 48 minutes and 46 seconds (365,438+09 days). Astronomical science tips 1. Stars are the most basic celestial bodies in the universe, which can emit light by themselves and are composed of hot gas, mainly hydrogen and helium.

2. The sun is a spherical celestial body composed of hot gas, and its main components are hydrogen and helium. The volume of the sun is about 6.5438+0.3 million times that of the earth.

The atmospheric structure of the sun is the external structure of the sun, which is divided into photosphere, chromosphere and corona layer from inside to outside. The period of solar activity is 1 1 year, and the main signs are sunspots and flares.

The influence of solar activity on the earth: (1) disturbing the ionosphere of the earth's atmosphere; (2) the phenomenon of "magnetic storm" occurred; (3) produce aurora. 3. Planets are nearly spherical celestial bodies orbiting the sun in elliptical orbits. They don't shine, and their mass is much smaller than that of the sun.

The eight known planets in the solar system are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. 4. solar eclipse when the sun, the moon and the earth run in a straight line, the shadow of the moon passes over the earth, which will cause an solar eclipse.

According to the degree that the sun is blocked by the moon, it can be divided into partial eclipse, total eclipse and annular eclipse. 5, eclipse When the sun, the earth and the moon run in a straight line, the moon runs into the shadow of the earth, it will form an eclipse.

According to the direct sunlight from the earth to the moon, it can be divided into partial solar eclipse and total solar eclipse.

5. How to write a composition on page 38 of the first volume of Chinese knowledge and ability training in senior two?

Give a picture or a title page! Forget it, I'll write one for you. Autumn is the season of falling leaves. The green leaves on the tree turned yellow. The breeze blew and the leaves danced like yellow butterflies. The geese in the blue sky saw the fallen leaves and cried as they flew, as if to say, "The telegram is coming, urging me to go to the south quickly!" " Autumn is the harvest season. Look, the endless rice is ripe. The heavy ears in Huang Chengcheng are so heavy that the rice stalks can't hold their waist. The autumn wind blows the ears of rice. It's beautiful. There is a pond next to the rice field, where small fish swim around as if playing hide and seek. Everywhere is red sorghum, which looks like a burning torch from a distance. The orchard is full of fruits, big and yellow. Red apples are like small lanterns. I love autumn, its golden color and its fruit.