用百分表测量柴油机气门头部和气门杆部的摆差,若分别大于(),即认为气门杆弯曲变形。 ["0.04mm和0.02mm","0.02mm和0.01mm","0.05mm和0.03mm","0.06mm和0.04mm"]
A.C.D.C.PD.C.PD-A.抗凝血液,4±2℃条件下各保存几天?() ["A.C.D保存21天.C.PD.保存28天.C.PD-A.保存35天","A.C.D-B.C.PD保存28天.C.PD-A.保存35天","A.C.D-B保存21天.C.PD.C.PD-A.保存35天","全部28天"]
需要采取措施增加其起激的可靠性的发电机是()。 ["主发电机","两级式无刷交流发电机","三级式无刷交流发电机","冲压涡轮发电机"]
平顺整修堤坡时,控制堤坡平顺的常用简易方法不包括()。 ["直尺法","挂线法","坡度尺法","锥探法"]
交叉配血不合时,哪些情况下可做抗体筛选?() ["有输血史.妊娠史或短期内需多次输血者","只要配血不合就做抗体筛选","常规筛选","必要时"]
什么是试管婴儿?如何生产试管婴儿?