---Have you decided already?
---Yes, I at once.
| A．have decided | B．decided | C．will decide | D．had decided |
The watch ______ unnoticed for several days before I found it.
| A．had laid | B．had lain | C．had been laying | D．had been laid |
—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 |