There is _______ “U” and _____ “S” in the word “useful”.
| A．a, an | B．an, an | C．an, a | D．a, a |
Thanks to better health care, more people are living _____ lives today than before.
| A．longer | B．richer | C．busier | D．easier |
The Science Museum is popular because people _____ do experiments there.
| A．can | B．must | C．would | D．should |
In America, you can open your presents immediately. You don’t have to ______!
| A．pay | B．wait | C．check | D．prepare |
Too much fast food is bad for us. We should only have it _____.
| A．all the time | B．from now on |
| C．at the moment | D．once in a while |
Our coach is pleased _____ we are playing better as a team now.
| A．so | B．if | C．because | D．before |