Many boys enjoy _______ football, basketball or baseball

Which do you think is ________, health or wealth？

_______________will not continue if an ongoing operation is changed or deletedA、

带传动中带的最大应力发生在______。

连杆机构的“死点”位置,将使机构在传动中出现______或发生运动方向______等现象。

29．__________ when you are on the bus or bike．

Which do you think is _________________important, health or wealth?

And they can ______their passports______，making leaving or “escaping” virtually impossible.

蛋白质属_____________，在碱性溶液中带______，在酸性溶液中带______。

Duty is an act or a course of action that people __________you to take by social customs, law or religion.

带电阻性负载的单相半波可控整流电路中,晶闸管承受的最大正向电压为_________,最大反向电压为_________。( )

带传动中,在同样的初拉力作用下,横截面为梯形的三角胶带和横截面为矩形的平胶带相比,承载能力_____________。