______ you understand the rule, you can do it well.
It’s a mistake to think of Chongqing only ______ its tourist attractions.
Is this the young engineer ________ you want to have ________ the computer for me?
-----They used to be good friends, but now they are like strangers. ----- How _____ this ______?
This new-type machine____________ little room.
The cattle _______ grazing on the grass.