A person needs to know who he/she is before being able to know what ___makes him or her happy.

Each life preserver must be readily accessible to the person for whom it is intended while he or she is（）.

Each life preserver must be readily accessible to the person for whom it is intended while he or she is（）.

Terri: Derrick, don't you think you should take a vacation? Even one or two days would be fine.Derrick:__________ There's too much work.

The（）enables water to be blow down or emptied from the boilerIt may be used when partially or completely emptying the boiler.

______no air or water, there would be no life in the world.

A bridge would cost far more than a tunnel, but you would be able to go by rail or by car on a bridge, whereas a tunnel would provide a rail link only.

I think you should end it ______ it is too late, or you will be sorry for it.

Vessels must be（）valid certificate of nationality or certificated of registry or license.

Effects which are dutiable or subject to prohibitions or restrictions should be declared in （）.

（）are liable to be stoten, pilfered or may damaged due to improper handing or stowage.

If you do not know the subject, you will not understand what is said or written, even if English is your mother （） what is said or written.