We need lots of ________ every day．
| A．healthy food | B．salads | C．milks | D．vegetable |
There were _________ doctors, so Dr Norman Bethune had to work on his own.
| A．few | B．a few | C．little | D．a little |
My little brother caught a cold, ________ he didn’t wear warm clothes yesterday.
| A．so | B．because | C．but | D．and |
I couldn’t work out this problem ________ my teacher helped me.
| A．before | B．unless | C．because | D．until |
_________ 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 |