----Why do you look sad? ----There are so many problems __________. A. remaining to settle B. remain

----Why do you look sad?
----There are so many problems __________.
A. remaining to settle B. remained settling
C. remaining to be settled D. remained to be settled
【答案】C
【解析】
【详解】考查remain的用法。句意：---你为什么看起来非常伤心？---因为还有很多事情待处理。sth remain to be done 某事有待于被做。many problems与settle在逻辑上是被动关系，所以用动词不定式的被动形式。故选C项。