It’s difficult to _______ who will be elected to chairman of the Student’s Union, for the two candidates are well-matched.
Look out! Don’t get too close to the house the roof is under repair.
Is some American friends visited last week?
. After two hours of walking, they came to the camp site, ______ .
. —______ that he managed to get the book? — Oh, his sister helped him.
The reason______ he was late for class is______ he didn’t catch the first bus.