As more and more cars are produced and used, so the _____ from their exhaust-pipes contains an even larger volume of poisonous gas.
| A．exposure | B．distribution | C．expansion | D．emission |
Doctors are often in ____ dilemma over whether or not to tell their patients ___ truth about their condition.
| A．a ; a | B．a ; the | C．/ ; a | D．/ ; the |
-- Must you play the guitar so loudly ? I can hardly ___ my book .
--- I’m sorry. I didn’t know you were reading .
| A．pay attention to | B．rely on | C．catch sight of | D．concentrate on |
Jack is late again. It is ___ of him to keep others waiting.
| A．normal | B．ordinary | C．common | D．typical |
--- Thank you for keeping me ___ of everything that’s happening.
--- Don’t mention it .
| A．inform | B．informed | C．informing | D．to inform |
We can hardly believe what she says because she is ___changing her mind.
| A．regularly | B．eventually | C．firmly | D．constantly |