do you think water can ___ some day?A.run out B.be run out C

un out/run out of
辨析：
run out = become used up 意思是“用完了,用了了”,相当于一个不及物动词,其主语通常为时间、食物、金钱等名词,后面不可以接宾语；run out of 意思是“用完了、用了了”,表示主动含义,主语一般是人,其后可以接宾语.如：
His money soon ran out.他的钱很快就花完了
His is always running out of money before payday.他老是发工资的日子还没到就把钱花完了.
keep out意思是“ 把……保持在外面”,也就是“禁止入内”.如：Keep that cat out of my study.
不要让猫进入我的书房.Keep it out.别让它进来（让它在外面）.
通过上述分析,可以肯定正确答案应该选A.“你认为水总有一天会用完吗?”