I've been waiting for him for ______ hour and ______ half.

There is nobody in the office ______ thereA．isn'tB．aren...

单项选择题There is nobody in the office ______ there

Please pay attention ______ what I say.A．toB．atC．of

单项选择题Please pay attention ______ what I say.

Be careful ______ your health.A．exceptB．ofC．to

单项选择题Be careful ______ your health.