I__________ __________ __________ (屏住呼吸) and hide behind the door. (breath)
我认为他住在那里,但我不敢肯定。I think he lives there but I couldn't say __________ __________.
A surgeon is a doctor who does __________(外科手术).
The fuel that p a machine provides the energy that the machine needs in order to work.
He has a good __________(掌握,精通)of English.
O shopping is cheap and convenient.