以下属于工程合同应包括的内容的是（）。
A.开工日期
B.竣工日期
C.工程造价
D.物资供应与管理
参考答案：A, B, C, D
计算题
Solve the puzzle to find out how many ping-pong balls are flying about here. The top ball is your answer. Answer: ____
2. What is twice a half of five and a half?
A. Ten and a half.
B. Five and a half.
C. Ten.
D. Two and a half.
Answer: _____
闭路磨机（）的高低对于磨机产量影响很大。
A.电耗
B.选粉效率
C.负载
