诱发肾功能不全加重的最常见因素是（）
A.感染
B.高血压
C.低钾血症
D.脱水
E.贫血
参考答案：A
Gary Locke , a Chinese-American, once______ as the governor of Washington for 8 years and now is U．S．Commerce Secretary．
A．had worked
B．worked
C．is working
D．has been working
—You know that you were driving at 100 kilometers per hour, don’t you?
—No, officer, I _____ have been. This car can’t do more than 80.
A．mustn’t
B．shouldn’t
C．may not
D．couldn’t
—You know that you were driving at 100 kilometers per hour, don’t you?