Having a trip abroad is certainly good for the old couple, but it remains _____ whether they will enjoy it.
A、to see
B、to be seen
C、seeing
D、seen
【正确答案】：B
【题目解析】：remain 是一个不及物动词，排除A。作为“留待”这个意思时，结构是remain to be done，所以选B。对于这对夫妻来说，能去国外旅游当然不错，但他们能否感到享受还有待观察。
