液化气钢瓶经测定，剩余壁厚小于设计壁厚多少的钢瓶应报废（）
A、80%
B、85%
C、90%
D、95%
参考答案：C
In your project，there is：25% probability for $25000 profit．50% probability for $40000 profit，25% probability for $100000 profit．What is the expected profit in your project
A．$40000．
B．$50000．
C．$51250．
D．$53750．
《钢铁是怎样炼成的》题目出自谁？
