While playing ping-pong, our eyes see the ball coming, judge its speed and then hit it back ________ it should go.
– I’m very tired. – We really should stop _____.
WHO is short _____ the World Health Organization.
I soon found that the work I was doing had already been done, _____, I was wasting my time.
She had stomach trouble and had to follow _____.
Our senior high school has _____ students as my junior high school.