( 2)         Crime is a big problem in many big cities. The police officers aren’t always able to stop everything on __6.__own. They can’t be everywhere at once, __7.__ they need help from other people.Now good citizens are making their jobs easier. Some of them will step in if __8.__. However, if there is anydanger to __9.__, they will call the police and let them know about the situation. Other people get together in groupsand walk around at night. If they see anyone doing anything strange, __10.__. If they can’t handle the situation,they will let the police know and keep an eye(注意) on things. It takes a lot to keep a city safe, so every little bit helps.

 * crime犯罪活動 at once 同時 citizen 公民 step in干預 danger 風險 situation 情況 bit 少量
【題組】6.
(A) their　
(B) his
(C) them　
(D) they