_______, Coca-Cola began to enter China’s market.
| A．In 1970’s | B．In 1970s |
| C．In the 1970s’ | D．In the 1970s |
_________ my mother was washing clothes, my father was reading books.
| A．While | B．When | C．Before | D．After |
When the first ______ came to the US, they were hungry as they have nothing to eat.
| A．students | B．pioneers | C．heroes | D．soldiers |
Spring is the best _______ of the year, because we can see lots of beautiful flowers.
| A．date | B．day | C．season | D．vacation |
I ________ the room yesterday, so it is not dirty today.
| A．clean | B．cleaned |
| C．will clean | D．is cleaning |
When the sun shines, the clouds _________ , and we can see everything much better.
| A．clear | B．clean | C．appear | D．leave |