—I’m not sure ______ Bill will come or not.
—No, he isn’t.
| A．when | B．if |
| C．whether | D．weather |
People often like clothes ______ can make them look young.
A. when B. who C. that
If more trees ______ planted, our city will be more beautiful.
A. were B. are C. will be
That man ______ be my English teacher. He has gone to Canada.
A. needn’t B. mustn’t C. can’t
－ ______ does your mother watch the Talk Show?
－ Once a week.
A. How long B. How often C. How soon
The students are helping the old man clean ______ house now.
A. her B. him C. his