Question

"Mary, turn off the water_________you are brushing your teeth. "  "Sorry, I'll do it at once. "
A. until          B. while          C. during

Answer 1

B

解析試題分析：句意: 瑪麗，當你刷牙時，關掉水龍頭。對不起，我馬上做。A. until 直到……為止，B. while 與……同時， C. during 在…..期間，據句意，故選B。
考點：考查連詞。