The advantage human beings have to the sun is worth discussing.
A man may usually be known by the books he reads _____ by the friends he keeps.
Although he is often tired _____ his work, he is never tired _____ his job. In fact, he enjoys it.
Is it true _____ the rain stops, it will be as hot as in the summer here?
— Is your mother still a teacher? — ______.
Because of the bad weather, my mother ____ and lay in bed. She ______ for a week.