题目

A major source of teen stress is school exams, and test anxiety is not common. When you recognize your teen is under stress, how can parents help your teen stay calm before an exam? Be involved. Parents need to be involved in their teen’s work. 36 What they look for is your presence -- to talk, to cry, or simply to sit with them quietly. Communicate with your teen. Encourage your teen to express her worries and fears, but don’t let them focus on those fears. Provide a calm setting. Help your teen set up a quiet place to study and protect his privacy. Give them a nutritious diet. I11．某同学在进行“测量滑轮组的机械效率”的实验时，设计了如下实验表格： 钩码总重G（N） 钩码上升高度h（m） 测力计拉力F（N） 测力计移动距离t（m） 2 0.050.8 0.15 （1）结合图，完成表格中两个未填的数据．（2）通过表中数据计算可得，提升物体所做的有用功为0.1J，滑轮组的机械效率为83.3%；（3）如果增大钩码总重，则滑轮组的机械效率将增大，如果增大钩码上升的高度，则滑轮组的机械效率将不变．（都选填“增大”“不变”或“变小”）