T610镗床的主轴和平旋盘是通过改变()的位置实现调速的。
A、钢球无级变速器
B、拖动变速器
C、测速发电机
D、限位开关
参考答案:A
一切历史都是现实,现实之外别无历史。所谓“现实之外”同“世界之外”一样,只在纯粹的语言学意义上和逻辑学意义上才有可能。现实之外并不是“非历史”,现实之前也不是“前历史”。我们不能说先有历史后有现实,而只能说有历史就有现实;既不能笼统地说历史先在于现实,也不能抽象地说历史使现实得以存在。 下列说法不符合文意的是( )。
A.历史存在于现实之中
B.没有现实就没有历史
C.历史与现实并无差别
D.“现实之外”并不存在
You want to know what the safest place for children 77.______is in the car The experts say the back seat is the safest for 78.______them. The back seat is farthest away off the force of a head- 79.______on collision(迎头撞击), which can lead serious injuries. 80.______If your child is below 8 and weighs no more than 85 81.______pounds, it is necessarily to fit your car with a safety seat. 82.______Moreover, the safety seat must be held in place of on the83.______car’s back seat. If your child do need your attention while 84.______you driving, don’t look back with only one hand on the 85.______wheel. You’d better stop the car. 86.______