_______ he is always studying hard is well known ____ us all.

If one of the computers _______, the whole networks would be unable to work.

The little time I had outside of school was _______ with work.

The officer ordered the policeman to __________ that tall man in a black hat. He thought the man might be the murderer wanted.

— Shall we go to the cinema this evening?
—Sorry I can’t. I’m __________ my mum at the airport at 7:00.

—______ can we get the photos?
—In two days.

Geography is the study of the countries of the world and of such things ______ the land, seas, climate, towns, and population.

I want to sell the house，but ________ I can’t bear the thought of moving.

In case of emergency, whether knowing how to apply first aid or not really ________ in matters concerning wounds like swollen wrists, broken arms, burns, cuts, and so on.

While studying， fix your mind on what is really important， or you will
         remembering nothing.