To keep a trade______, they would have to sell less and buy more in the following months.
| A．pace | B．distance | C．balance | D．increase |
If you miss this chance, it may be years ____ you get another one.
| A．As | B．before | C．since | D．after |
I just heard____ bank where Dora works was robbed by____ gunman wearing a mask.
| A．the; / | B．a; / |
| C．the; a | D．a; the |
Niki is always full of ideas, but is useful to my knowledge.
| A．nothing | B．no one |
| C．neither | D．none |
Little Tom sat watching the monkey dancing in front of him.
| A．amaze | B．amazing |
| C．amazed | D．to amaze |
The exhibition tells us we should do something to stop air pollution.
| A．where | B．why | C．what | D．which |