如图所示，在一直流电动机的气隙中（磁极和电枢之间的区域），磁感应强度为0.8T．

新光小学的操场是一个长方形，画在比例尺是1：4000的平面图上，长3厘米，宽2厘米，操场的实际面积是  [ ]

A. 240平方米  

B. 96平方米 

C.2.4平方米    

D.9600平方米

一个蓄水池是圆柱形的，底面面积为31.4平方分米，高2.8分米，这个水池最多能容多少升水？

站场、厂房、作业场地夜间要有足够的（）；道口、弯道处要有明显的（）。

According to a report, the birth sex ratio in China is still out of proportion and could cause serious imbalance among the people in the decades ahead, with millions of men in China unable to find wives.

Topic: Imbalanced birth sex ratio

Questions for Reference:
1. What might the serious imbalance suggest
2. What can the government do to remedy the situation
3. Do you think the situation will improve in the near future

以下哪个不是共享权限（）

A.fullcontrol

B.change

C.modify

D.read