【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.
【简答题】设生产某种产品Q件的成本函数为C(Q)=1000+5Q,出厂单价为10元,则该厂每天至少生产( )件该产品才不亏本。
【单选题】Who is going to______your mother while you are away?
【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.