电感为0.1H的线圈，当其中电流在0.5秒内从10A变化到6A时，线圈上所产生电动势

下列各句中均有一处错误，请找出并改正在句后的横线上。

1. The forth day of the week is Wednesday.                    ____________________                

2. Mario is a unusual piano player.                                  ____________________

3. March 8th is Woman's Day.                                       ____________________   

4. Deng Yaping join the national table tennis team in 1985. ____________________

5. Pele was a great Brazil soccer player.                           ____________________

6. You was born on March 3rd.                                      ____________________

7. The girl was born in the morning of July l^st.                 ____________________

8. This is the begining of the garden tour.                         ____________________

图所示的四个选项中，应用到电磁铁的是： [ ]

A.指南针

B光盘.

C.电铃

D.磁卡

根据作业高度H的不同，可能坠落范围的半径R也不同，当H为15～30米时，R为：米

A．2

B．3

C．4

D．5

抗体释放试验(antibodyreleasetest)

使用胶片自动洗片机时，如果干燥器的温度和空气循环均正常，则引起胶片干燥不良的原因可能是（）

A、定影液补充不足

B、洗片机不常使用而内部潮湿

C、水洗槽中辊棒不正

D、过显影