Before traveling in space, you must know what it might feel likein an imaginary environmen

网友回答

(答案→)A. to travel
B. traveling
C. to be traveling
D. travel
解析：本题易受到feel like doing sth的影响而误选B, 此处feel like的意思为 “感觉象什么”, it 为形式主语,真正的主语为不定式短语。句意：太空旅行前，你必须知道在模拟环境下行走时的感觉。