The river smells terrible. People must_____ dirty things into it.
| A．be prevented to throw | B．prevent from throwing |
| C．prevent to throw | D．be prevented from throwing |
The art club is for members only. You can’t go in _______ you are a member.
| A．unless | B．because | C．if | D．though |
She likes doing her homework _______ the radio _______.
| A．to, with | B．on, with | C．with, on | D．with, open |
In winter, we must pay attention to _________.
| A．keep warm | B．keep warmly | C．keeping warm | D．keeping warmly |
He thinks watching movies ________.
| A．frustrated | B．frustrating | C．frustrate | D．to frustrate |
When we practice speaking English, we often end up _______ in Chinese.
| A．to speak | B．speak | C．spoken | D．speaking |