Air and the sun's rays create much distortion, and whatever tends to _____ their influence is useful to the astronomer.
The students entered the classroom,smiling and________,and ______ down to have their lessons.
He kept a little notebook, in which the names and addresses of his friends.
that her mother would come back soon, the girl calmed down.
—Why? Tom,your skirt is so dirty! —Mum, I my storeroom downstairs.
I’m sure you will do better in the test because you so hard this year.