–Would you mind us asking you a few questions?
–_______.
| A．Yes. Go ahead. | B．Not at all. You’d better not. |
| C．Not at all. Go ahead | D．No. I don’t mind. |
____much advice I gave him, he did exactly what he wanted to do.
| A．How | B．However | C．Whatever | D．No matter |
Generally speaking, _____ according to the derections , the drug has no side effect.
| A．when to take | B．when taking | C．when to be taken | D．when taken |
Someone called me up in the middle of the night, but they hung up _____ I could answer the phone.
| A．before | B．as | C．since | D．until |
--- May I go and play with Tom this afternoon, Mum?
---No. You can't go out _____ your homework is being done.
| A．until | B．since | C．before | D．if |
The idea of fish being able to produce electricity strong enough to light a lamp is almost unbelievable, _____ several kinds of fish are really able to do this.
| A．therefore | B．and | C．then | D．but |