Exploring space is exciting, yet dangerous. There is need for both robots and humans for space exploration.
A. the; a
B. a; a
C. /; a
D. /; the
网友回答
A. the; a
B. a; a
(答案→)C. /; a
D. /; the
解析：句意：探索太空是令人兴奋的，然而也是危险的，太空探索即需要机器人也需要人类。第一空不填，space是抽象名词，第二空填a，There is a need for..“有…需求”，所以选C。