My mother is always warning me when I go out, “Don’t get off the bus ____ it is stopping.”
| A．until | B．before | C．while | D．after |
—What do you think of his opinion?
—None has given me ___________ piece of advice.
| A．a better | B．a best | C．the best | D．the better |
It has been proved _______ eating vegetables in childhood helps to protect you against serious illnesses in later life.
| A．if | B．that | C．what | D．when |
It is reported that the United States uses ____ energy as the whole of Europe.
| A．as twice | B．twice much | C．twice much as | D．twice as much |
________ you are interested in astronomy, you can read the book.
| A．Even if | B．Now that | C．Unless | D．As soon as |
_________ parents say and do has a life-long effect on their children.
| A．That | B．Which | C．What | D．As |