Cycling is highly __________ to people’s health and the environment.

What happened to him —He was murderlast week. A．guiltyof

Ken has gone to the Africa country to work as a volunteer.— I would rather he _____there. The situation there is very tense.

Yesterday if the policeman _______earlier,the fight between the two boys would have been prevented.

________ is often the case with her, my mother talked about my study for at least half an hour nonstop before she drove me to school yesterday.