【单选题】______yourself while you are away.
【单选题】听力原文:M: You look like you are freezing to death. Why don't you put this on? W: Thank you, it was so warm at noon, I didn't expect the weather to change so quickly. Q: What do we learn from the convers...
A.
The woman didn't expect it to be so warm at noon.
B.
The woman is sensitive to weather changes.
C.
The weather forecast was unreliable.
D.
The weather turned cold all of a sudden.
【判断题】发电机是汽车上的主要电源,它与蓄电池串联。
【简答题】设某产品的市场需求函数为Q=1000-10P,成本函数为C=40Q,试问:
【简答题】设某产品的需求函数和总成本函数分别为Q=2000-50p, C=C(Q)=1000+20Q, 求利润最大时的产量、产品的价格和最大利润.
【简答题】IF 函数几个参数 , 且第一个参数要选中几个单元 格 ?