我很高兴听到许多关于安全的建议。
A. It is glad for me to hear many suggestions about safety.
B. I am very glad to hear many suggestions about human life.
C. I am very glad to hear many suggestions about property security.
D. I am very glad to hear many suggestions about the main engine.
备件即将运往船上。
A. I have already started the work.
B. I am working now
C. The spare parts were delivered on board.
D. The spare parts will be delivered on board.
对于普通的初等函数，如果函数的图像是严格单调上升（或严格单调下降），那么函数是单射的。
A. 对
B. 错
设 A={1,2,3,4}，则A的幂集P(A)中有个元素
微信支付 
支付宝支付