多选下列说法正确的是( ) A.当作用力做正功时,反作用力一定做负功 B.当作 发布时间:2017-07-29 04:11 │ 来源:www.tikuol.com 题型:多选题 问题: 多选下列说法正确的是( )A.当作用力做正功时,反作用力一定做负功 B.当作用力不做功时,反作用力也不做功 C.作用力做正功,反作用力也可能做正功 D.作用力与反作用力的功大小不一定相等
题型:多选题 Mr. Taylor, of the urban life, is considering his last years in the countryside after his retirement. A.tiring; spendB.tired; to spendC.tiring; spending D.tired; spending 查看答案