问题补充:
There are a great number of natural resources in the desert, which remain to be .
A. explored
B. exploited
C. exploded
D. exposed
答案:
A. explored
(答案→)B. exploited
C. exploded
D. exposed
解析:考查固定词组。固定词组sth remain doing/to be done某事有待于被做;句意:在世界上有很多的自然资源,他们都有待于被开放利用。故B正确。