I don’t think difficult for a Chinesestudent to master a foreign language within five years

Must I hand in my homework now—No,you__.You can hand it in tomorrow.

Did he come back late last night? —No．It was not yet eight o’clock _____________ he arrived home

While cleaning thesnow on the road, _________.

f danger in the street at night, shehad to go home, with a friend ____ her