Anyone ______ trying to take knives on heard flights would be caught by the police.
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.
Such a problem is____difficult for a primary school student ___.