The agent was about to sign his name to the document_______ , to our surprise, a stranger broke in to prevent him.
| A．while | B．when | C．as | D．until |
_________ in the leg made it impossible for him to walk home.
| A．Injured | B．Having injured | C．To be injured | D．Being injured |
I used to drink a lot of tea but these days I _________ coffee.
A. preferＢ. preferred C. have preferred D. am preferring
–What should I do first?
--The instructions _________ that you should mix flour with water carefully first.
| A．say | B．tell | C．write | D．go |
Pleasant music is often played _________ classes to make students refreshed and relaxed for a while.
| A．after | B．between | C．among | D．over |
二、单项选择
Don’t worry too much about ________ mistakes. They’re ________ natural part of learning something.
| A．the; the | B．/; the | C．the; / | D．/; a |