Three quarters of some children’s spare time　　　　 wasted watching TV －that can explain why they are lazy.

 The drug used to treat this disease causes bad side effects, some of which ________ deadly.

--- How _____ hours do you sleep a day?--- Well, about eight hours. But how _____ sleep do we students really need?

The poster says that a writer and poet ___ to give us a talk on English next week.

—Does the old man know the museum very well? —No, this is the first time he __________ here.