52．A．outside                  B．out of                   C．into                       D．inside

51．A．to weak                 B．strong                  C．weak                     D．healthy

50．A．to sleep                 B．sleeping                       C．slept                    D．to sleeping

49．A．to                       B．for                        C．with                             D．of

48．A．will have             B．can have              C．won't have              D．have

47．A．ten hours               B．ten hours'              C．ten hour's               D．ten-hours'

46．A．enough                 B．many                    C．some                     D．very

45．We all know that it is very kind _________ him _________ us．

A．for…to help          B．of…to help            C．for…helping          D．of…helps

Everyone must go to bed early and get up early，or we won't be healthier and clever．

Is this true? Perhaps it is．The body must have __46__ sleep．Children of your age need __47__ sleep every day．If you don't go to bed early，you __48__ enough sleep，then you can’t think properly and can't do your work properly．You will not be clever．

Some people go to bed late and get up late．This is not good __49__ them．We must sleep at nine when it is dark．The dark help us __50__．When the daytime comes，we must get up．This is time for exercises．If you lack exercises，it becomes __51__．Exercises help a strong body．

Exercises help the blood（血液）flow around __52__ the body．This is very important．Blood takes food __53__ all parts of our body，the brain（大脑）needs blood．We think __54__ our brain．If we keep our body __55__ and take exercises，we can think better．

44．--Why were you late?

--Because I have no money _________ the bus．And I had to walk here．

A．on                         B．take                       C．by                         D．for

43．When I got to the house，found a backpack _________ on the ground．

A．lie                         B．lay                        C．lying                     D．be