There are a great number of natural resources in the desert which remain to be .A. explor

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。