— I've taken someone else's green sweater by mistake.— It ________ Harry's. He always wears green.
A. has to be B. will be C. mustn't be D. could be
The policeman's attention was suddenly caught by a small box which _______ placed under the Minister's car.
A. has been B. was being C. had been D. would be
He hurried to the station only ________ that the train had left.
A. to find B. finding C. found D. to have found
The American Civil War lasted four years ________ the North won in the end.
A. after B. before C. when D. then
I think he's just going to deal with this problem ________ day.
A. next B. other C. following D. another
Years ago we didn't know this, but recent science ________ that people who don't sleep well soon get ill.
A. showed B. has shown C. will show D. is showing