Mr. Smith didn’t go to the party because he had a lot of experiments _____.
| A．do | B．did | C．done | D．to do |
. —Can you help raise some money for the new journalist’s amusement center?
—_____. But give me some time.
| A．Thanks | B．Go ahead | C．Sure | D．Sorry |
—I don’t believe we _______ before.
—Well, I saw you once at a party, but we ______ introduced.
| A．have met; weren’t | B．met; weren’t |
| C．have met; haven’t been | D．met; haven’t been |
I waved to Nancy, but she was ______ in her thoughts, and made no response.
| A．involved | B．stuck | C．absorbed | D．interested |
You must observe and gather information like Nicolaus Copernicus ________ you want more career advancement opportunities.
| A．or | B．because | C．unless | D．if |
_______ in this way, the result seems unsatisfactory, so we’d better have another try.
| A．To look at | B．Looking at | C．Looked at | D．To be looking at |