问题 单项选择题

泵轴弯曲造成轴承发热故障时,应()。

A.更换轴承

B.调整水泵和电机两轴中心

C.校正轴

D.调整轴承间隙

答案

参考答案:C

选择题
填空题

读课文,写句子。   

1.能看出“非洲是一个色彩斑斓的世界”的句子有:                                                                          

                                                                                                                                                             

2.课文中首尾照应的句子是:                                                                                                              

                                                                                                                                                             

3.课文中描写的人文景观有: