run out/run out of
辨析：
run out = become used up 意思是“用完了,用了了”,相當(dāng)于一個(gè)不及物動(dòng)詞,其主語(yǔ)通常為時(shí)間、食物、金錢等名詞,后面不可以接賓語(yǔ)；run out of 意思是“用完了、用了了”,表示主動(dòng)含義,主語(yǔ)一般是人,其后可以接賓語(yǔ).如：
His money soon ran out.他的錢很快就花完了
His is always running out of money before payday.他老是發(fā)工資的日子還沒(méi)到就把錢花完了.
keep out意思是“ 把……保持在外面”,也就是“禁止入內(nèi)”.如：Keep that cat out of my study.
不要讓貓進(jìn)入我的書(shū)房.Keep it out.別讓它進(jìn)來(lái)（讓它在外面）.
通過(guò)上述分析,可以肯定正確答案應(yīng)該選A.“你認(rèn)為水總有一天會(huì)用完嗎?”