As we have known from the map of the world，this is ________.

—What’s Jack up to in the shoe shop? He’s there for ages.—It’s ______ that he hasn’t decided which pair to buy.

Can you tell me the        difference between the words “require” and “request” ? I sometimes get puzzled by their meanings.

— Will you be         this afternoon, John?— I am afraid not. I have an appointment with my dentist.

Be ______ — you can’t expect me to finish all this work in so little time.