【简答题】Problems concerning work may often involve a force that act as in a direction different from the direction of the motion of a body it is acting on. 20. During the fraction of a second that the two bal...
【单选题】W: Oh, Darling, have we done everything on the list? M: Let's see ... Bank, post office, airline office, shoes. We haven' t booked our hotel room yet, but I' II do that on the telephone tonight. 22. W...