33. When a student asks_________it is worth staying up doing their lessons, a teacher may find it difficult to answer.
11.There is no light on--- they _______ be at home.
10.--- Hello, John here, can I speak to Mary , please? ---_____________.
9._____ makes this shop different is that it offers more personal services.
8.Although this_______ sound like a simple task, great care is needed.
7.Please ______ your sister to bring the ticket for the concert.