给水泵流量极低保护的作用是（）。
A、防止给水中断
B、防止泵过热汽化
C、防止泵过负荷
D、防止泵超压
参考答案：B
— Math is difficult for me. How I wish to improve it!
— Don't lose your confidence. I believe you will _____ it if you keep trying. [ ]
A. take
B. work
C. pick
D. make
简述公共物品私人供给的可能性。
