输卵管绝育术的作用是
A.抑制排卵
B.杀灭精子
C.阻止精子与卵子相遇
D.降低宫颈粘液的粘稠度
E.降低精子存活率
参考答案:C
--- We can go swimming in the lake in summer. But why don’t you like it?
--- Because it’s ___________.
A.too much hot
B.much too hot
C.more hotter
D.so hotter
如果卧式升降台铣床工作台纵向移动对工作台面的平行度超差,当用角铁安装工件铣平面,且角铁装置面与进给方向垂直,则会影响工件的平行度。