下列关于重力势能的说法中，正确的是 A．重力做正功，重力势能减少 B．重力做负功 发布时间：2017-07-30 13:17 │ 来源：www.tikuol.com 题型：选择题 问题： 下列关于重力势能的说法中，正确的是A．重力做正功，重力势能减少B．重力做负功，重力势能增加C．重力不做功，重力势能不变化D．重力势能变化与重力做功无关
题型：选择题 完形填空. Boys and girls love to watch TV. Some children 1 six hours a day in the school and sit four to six hours a day 2 the TV sets. Some children even (甚至) watch TV for eight or 3 hours at weekends. Sometimes TV programs (节目) are 4 and a child can know a lot of things from them. It’s very 5 to watch TV. 6 sometimes TV can also teach children some 7 things. It’s not good for children to watch 8 TV and it’s bad for their 9 , too. So, boys and girls, don’t watch too much TV. It’s also very interesting to read 10 or to visit friends.( )1. A. study ( )2. A. before ( )3. A. many ( )4. A. helps ( )5. A. interest ( )6. A. And ( )7. A. good ( )8. A. too ( )9. A. eye ( )10. A. books B. studies B. beside B. more B. help B. interestingB. Or B. bad B. too many B. eyes B. newspaper C. to study C. in front ofC. much C. helpful C. fun C. But C. important C. too much C. ear C. pictures D. studyingD. near D. lots of D. helping D. funny D. So D. helpful D. much D. ears D. map 查看答案