. “This is a window, ________ the sun comes in.” said the lady to her baby.
| A．where | B．which | C．by which | D．through which |
As is known to all language learners, newly learnt words will soon be forgotten unless ______ used in everyday communication.
| A．exactly | B．finally | C．gradually | D．frequently |
Many students listened to the lecture, but I wondered how much they ______.
| A．took out | B．took up | C．took off | D．took in |
I think that something has to be done to stop the air from being polluted, ______ ?
| A．doesn't it | B．don’t I | C．don't they | D．haven't they |
It has been reported that some government leaders ______ their authority and position to get illegal profits for themselves.
| A．overlook | B．employ | C．abandon | D．abuse |
Let's learn to use the problem we are facing ______ a stepping-stone to future success．
| A．to | B．for | C．as | D． by |