What does Bob have to do?
A:Wash the dishes.
B:Make dinner.
C:Clean the house.
图甲所示,是“研究水沸腾时温度变化特点”的装置图.
求此吊车从索道最高处运行到最低处重力所做的功。
—Why are you in such a hurry.Mike?
—There a badminton match in ten minutes.