阅读短文,从方框中选择适当的词并用其正确形式填空,使短文通顺、意思完整。每空限填一词,每词限用一次。
方框内单词：good, certainly, early, when, hour, help, health, mind, strong, be, also
Going to bed early and doing more exercise 61 good for us. Everyone must go to bed 62 and get up early and do some exercise, or we won't be healthy and clever.
Is it true? It 63 is. The body must have enough sleep. Middle school students need eight 64 sleep every day. If you don't go to bed early, you won't have enough sleep. Then you can't think carefully and can't do your work 65. You'll not be clever.
Some people go to bed late and never do sports. This is not good for them. We must sleep at night 66 it is dark. The dark 67 us to sleep well. When the daytime comes, we must get up. This is the time for exercise. Exercise keeps a 68 body.
The brain 69 needs blood(血液). If you don't exercise, the body will become weak. Our 70 will not be clever. Exercise helps the blood flow(流动) around inside the body. This is very important. Blood takes food to all parts of our body. We think with the brain. If we keep our body 71 and take exercise, we can think better.
61. is
62. early
63. certainly
64. hours'
65. well
66. when
67. helps
68. strong
69. also
70. mind
71. healthy

61.are 62.early 63.certainly 64.hours' 65.well
66.when 67.helps 68.strong 69.also 70.mind
71.healthy