问题 单项选择题

最大秤量为20t,检定分度值e为5kg的电子汽车衡,零点或零点附近的误差可用()的砝码进行称量,并经计算得出。

A.30e

B.10e

C.20e

D.40e

答案

参考答案:B

多项选择题

观察下面工业革命时三种机器图片,回答问题

图一
 图二
图三

(1)图一所示机器的发明者是谁?它的技术突破体现在哪里?说说它的出现对工业革命的影响。                                                                                                                                                                                                                                                                                                                                  (2)图二所示机器的发明者是谁?说说它在工业革命中的作用。                                                                                                                                                                                                                                                                                                                                   (3)图二所示机器与图三所示机器之间有什么内在联系?