Can the twelve constellations be seen at the same time?

Not if it's in China! Different constellations will appear in different seasons. The twelve constellations are on the ecliptic, which is a circle around the earth. How can you see them at the same time outside the equator?

References:

In astronomy, the orbit of the sun around the earth with the earth as the center is called the ecliptic. The width of the ecliptic is 16 degrees, 360 degrees around the earth. The ecliptic plane includes the orbits of all planets except Pluto, as well as the constellations, exactly every 30 degrees.

Each interval has a constellation, a total of twelve constellations, called the "Zodiac".

The sun runs from west to east on the ecliptic and circles the sky once a year. There are twelve constellations on a belt on both sides of the ecliptic. They are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. People on earth can see them one after another in a year.