Everyone may feel time____ very quickly when they do something interesting.
A．go by B．to go by
C．went by D．going by
Our English teacher often says to us,“____ English well is very important.”
A．Learn B．Learning
C．Learned D．To learning
Many children are left alone in the countryside. Let’s try our best ____ them.
A．help B．helping
C．to help D．helps
—What about _____ a rest?
—Let's go for a walk.
A．to take B．take
C．taking D．taken
He lost his key. It made him _____in the cold to wait for his wife’s return．
A．to stay B．stayed
C．stays D．stay
She’s not strong enough _____ walking up mountains.
A．to go B．going
C．go D．went
