Nowadays, many people________about eating habits _________what they believe.
| A．take choices; base on | B．make choices; based on |
| C．do choices; basing on | D．have choices; to base on |
______ around the cultural relics for almost an hour, we got together under a big tree for a short break.
| A．Having shown | B．Having been shown |
| C．To show | D．To be shown |
---He ought to have been warned of the danger.
---_______, but he wouldn’t listen to me.
| A．He did | B．He should | C．He ought to | D．He was |
---You may find the key to the maths problem on page 107.
---Ah, it’s so simple. I wonder why I ________ of that.
| A．didn’t think | B．haven’t thought | C．wasn’t thinking | D．hadn’t thought |
----You seem to have known Dr Smith for a long time.
---- That’s true. ______ he joined our club six years ago.
| A．Since | B．Until | C．When | D．Before |
----I don’t mind telling you what I know.
----You ________. I’m not asking you for it.
| A．mustn’t | B．needn’t | C．may not | D．shouldn’t |