—Where did you get this book?
—I picked it up from a second-hand bookshop if you ______know.
| A． must | B．will | C．can | D．shall |
The university estimates that living expenses for international students________around $8,450 a year，which________a burden for some of them. (2013·湖南，33)
| A．are；is | B．are；are |
| C．is；are | D．is；is |
At no time________the rules of the game.It was unfair to punish them. (2013·辽宁，26)
| A．they actually broke |
| B．do they actually break |
| C．did they actually break |
| D．they had actually broken |
________small，the company has about 1,000 buyers in over 30 countries.(2013·天津，5)
| A．As | B．If |
| C．Although | D．Once |
Only by increasing the number of doctors by 50 percent ________ properly in this hospital. (2013·大纲全国，32)
| A．can be the patients treated |
| B．can the patients be treated |
| C．the patients can be treated |
| D．treated can be the patients |
It was only after he had read the papers ________ Mr.Gross realized the task before him was extremely difficult to complete. (2013·大纲全国，30)
| A．when | B．that |
| C．which | D．what |