Great as Newton was, many of his ideas _______ today and are being modified by the work of scientists of our time.
| A．are to challenge | B．may be challenged |
| C．have been challenged | D．are challenging |
——May I put my luggage on the seat beside you, sir?
——____.
| A．Sure, with pleasure | B．Okay, please yourself |
| C．Well, never mind | D．Yes, help yourself |
What he ____ ,to be frank, ____ please us present.
| A．does; do | B．does; does | C．do; do | D．do; does |
The company has a free long-distance telephone number_____ customers may call with any questions they have about the products .
| A．when | B．so that | C．while | D．as |
I know the man ____chance, but I have never spoken to him.
| A．with | B．on | C．for | D．by |
---Must I go to work with you?
--- No, you_____. Linda ______ go with me.
| A．mustn’t ; can | B．can’t ; has to | C．daren’t ; should | D．needn’t ; may |