21. Could you drive me to the supermarket at noon if______?
A. it’s convenient of you B. you are convenient
C. it’s convenient to you D. you will be convenient
【解析】选C。convenient意为“方便的，便利的”，不能用人作主语，表示“某人方便做某事”应是：It is convenient for sb. to do sth. 或sth. is convenient to sb. 故答案选C。句意为：中午如果你方便的话能开车送我去超市吗？
Would it be _______ for you to pick me up at four o’clock and take me to the airport?
A. free B. vacant C. handy D. convenient
