策动力频率等于受迫振动物体固有频率时,振幅最大,这种现象叫做()。
参考答案:共振
Follow the Chinese. Fill in the blanks. 根据中文提示,完成下列句子。
1. Li Ming flies a____ (风筝) in summer.
2. There are some____ (小鸟) in the sky.
3. I like to play in the____ (池塘) in summer.
4. Danny is____ (害怕的), because he can't swim.
5. Jenny runs____ (快) than Danny.
6. I am going to lie on the (草地).
7. Do you have a ____(兔子)?
8. We usually ____(跳绳) on Sundays.
9. Look at the ____ (美丽的) flowers in the park.
10. What did you do in the ____ (暑假)?
男性腹型肥胖的定义为()。
A.腰围≥75cm
B.腰围≥80cm
C.腰围≥85cm
D.腰围≥90cm
E.腰围≥95cm