Taking regular exercise and eating a balanced diet are two important keys ________ good health.
He came to my class every week, but his attitude ______ he was not really interested in the subject.
To tell ______ truth, he is at ______ loss what to do currently.
--Alice, turn off the light and lock the door before you leave. -- ______.
---How are you getting on with your classmates? ---______. I’ve got to know them all.
Rose is Mr. Smith’s secretary, so she has _____ to all his business e-mail.