. He must be curious about everything in the lab, for this/that/it is the first time that he has been there, ________?
| A．isn’t he | B．mustn’t | C．isn’t it | D．hasn’t he |
I’d like to buy a house --- modern, firm, comfortable, and ________ in a quiet neighbor-hood.
| A．in all | B．above all | C．after all | D．at all |
They usually have the medicine_______ before putting into the market all over the country.
| A．testing out | B．to be tested out |
| C．being tested out | D．tested out |
---Where is your new home now?
---In the new developed zone. But I _____ downtown for five years.
| A．have lived | B．had lived |
| C．lived | D．was living |
—Hi, Mr．Brown! May I pick a flower in the park?
—_______.
| A．No, you don’t | B．No, you mustn’t |
| C．No, go ahead | D．Yes, you could |
This problem is said _______ three times, but he still can’t understand it.
| A．to have been explaining | B．to have explained |
| C．having been explained | D．to have been explained |