the next day they found that the door remained -,and that the boss was gone .

题目

the next day they found that the door remained -,and that the boss was gone .
a.to lock b.locking c.locked d.to be locked

答案

C
remain 可以加现在分词和过去分词.加现在分词时表主动含义,用过去分词时表被动含义.
the next day they found that the door remained locked 第二天,他们发现门仍然锁着.
门要被锁,因此选过去分词locked
remain用法详解
1）当保持(某种状态)继续存在时,后面接形容词、名词、分词和介词短语.
e.g．They will remain in contact with us．
他们将与我们保持联系.
After years of hard work,Tom still re-mained a worker．
多年的辛劳后,汤姆仍是一名工人.
That old man remained full of energy．
那位老人还是那么精力充沛.
The situation remained unchanged．
局势没有什么变化.
She remained sitting when they came in．
他们进来时,她仍然坐着(没有站起来)
2)停留,逗留(continue in some place).用作不及物动词.
e.g．Please remain here till I return．
请留在这儿,等我回来.
He seldom remains in his office．
他很少呆在办公室里.
(3)剩下、遗留(be still present after a part has gone or has been taken away).用作不及物动词.
e.g．If you take 4 from 9,5 remains．
九减四剩五.
Few people remained in the meeting-room．
会议室的人所剩无几.
当“剩下、留下”讲时应注意以下两点：
a．可与不定式连用
e.g．A lot of work remains to be done in the office．
办公室里待做的工作很多.
Many problems remain to be settled．
很多问题尚待解决.
b．用现在分词remaining(剩下的、剩余的)作定语.
e.g．The old man didn"t know how to deal with the remaining vegetables．
这位老人不知道怎么来处理剩余的蔬菜.
The boy ate up the remaining food．
这个男孩把剩下的食物全吃了.