体育老师对六年级女生进行仰卧起坐达标测试，以每分钟做40个为标_爱下问搜题

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问题解答题

体育老师对六年级女生进行仰卧起坐达标测试，以每分钟做40个为标准，超过次数用正数表示，不足次数用负数表示，老师记录这九个同学的成绩如下：

3

-2

0

4

-3

1

0

5

-2

（1）9名女生中有百分之几达到标准？
（2）9名女生平均做了多少个仰卧起坐？

答案

（1）6÷9×100%≈66.7%；

答：9名女生中有66.7%达到标准

（2）[40×9+（3-2+0+4-3+1+0+5-2）]÷9，

=[360+6）÷9，

=91.5（个），

答：9名女生平均做了91.5个仰卧起坐．

多项选择题

IC卡系统由什么组成（）。

A、车道指示灯

B、IC卡读写器

C、IC卡

D、微笑视频

完形填空

Do you know how much your children sleep?
According to the National Sleep Foundation,       should sleep twelve to eighteen hours       of every twenty-four. With a gradual        to twelve to fourteen hours for toddlers(初学走路的孩子) one to three; eleven to thirteen hours for        three to five; and ten to eleven hours for schoolchildren        five to ten.
But things get really      at adolescence. Not only do teenagers need more sleep than    __---eight and a half to nine and a quarter hours a night, according to the sleep foundation - but the times          which they get sleepy and are able to awaken         and feel rested shift in a       that does not match to the       times at most schools.
Sleep studies have shown that the typical teenager does not fall asleep readily before 11 p. m. or later.       many have to get up by 6 a. m. or         to get to school for a class         starts at 7:30 or 8 a.m. More than a few        off during that class, and often the         one as well. Even if awake, they're in no condition to learn much of anything.
In one study, more than 90 percent of teenagers        they slept less than the          nine hours a night, and 10 percent said they slept less than six hours.
      _ James B. Maas, a Cornell University psychologist and Leading sleep researcher, has observed, most teenagers are "walking zombies(僵尸)"        they get far too little sleep.

D．improvement

D．preschoolers

B．challenging

D．encouraging

D．schoolchildren

D．examination

B．recommended

D．Furthermore