污水泵电机过载的原因及处理?
参考答案:
(1)填料压得太紧(调松填料压盖)。
(2)转动部分发生摩擦(消除磨擦)。
(3)轴承损坏(更换轴承)。
(4)泵轴弯曲(更换泵轴)。
So far all cloned animals have suffered from some different serious disorders, _____ dying soon after birth. [ ]
A. many of which
B. many of whom
C. many of them
D. many of that
千斤顶的选择正确的是()。
A、千斤顶的顶升高度不用超过螺杆或活塞总高的3/4
B、使用几台千斤顶顶升重物时,宜选择不超过两种型号的千斤顶
C、顶升重物时,应随重物下垫保险钢管
D、千斤顶放置位置与被顶物之间应保持夹角不大于30℃