She had to leave school_______ her family couldn’t afford her education.
A. although B. unless
C. because D. so
The old man has retired from the factory. He _____ there for 30 years.
A. works B. worked
C. has worked D. was working
— I don’t mind telling you what I know.
— You _______. I can manage it myself.
A. mustn’t B. ought not to
C. can’t D. don’t have to
—Have you heard of the accident on this road last night?
—Yes. And there ________ three accidents here so far this year.
A. are B. were
C. have been D. had been
The students _______are hard-working and ready to help should be praised.
A. who B. whom C. which D. whose
— What’s the noise outside?
— Some children ________ hide-and-seek in the yard.
A. were playing B. are playing
C. have played D. played
