The train starts（ ）6:20，so you’d better get there before 6.

A.on B.at C.in D.of

Now I（ ）to work by bike instead of by car as there are too many cars on the road in rush hours.

He studied hard at school when he was young,（ ）contributed a lot to his success.

Researchers have spent five years collecting data（ ）the study was based.

All students are required to translate this poem（ ）English into Chinese.

A. Going to bed at 10 p. m. is B. a order that must C. be obeyed by everyone D. here.