90. ____ the work was very difficult, they managed to finish it in time.
| A．Because | B．Though | C．Therefore | D．But |
271. Wait for me for a few more minutes. I am _____ to a letter from one of my former classmates at college and will finish writing very soon.
| A．replying | B．answering to | C．replying to | D．answering for |
270. Hoping that they would ______ the rent a little, we pointed out all of the flaws in the apartment.
| A．reduced | B．reduce | C．increase | D．Fell |
269. Although he didn't mention any names, everyone knew _____ he was _______.
| A．who … referring to | B．that … referring to |
| C．who … refers to | D．that … referred to |
268. Yesterday one of my classmates sent me an invitation to take part in an English evening, but I _____ for the reason that I caught a bad cold.
| A．refused | B．accepted | C．received | D．Took |
267. After throwing the lamp against the wall and turning over the dining room table, she deeply ______ her temper.
| A．regretted losing | B．regretted being lost |
| C．regretted to lose | D．regretted to be lost |