When asked why he went there,he said he was sent there for a space flight.
A. training
B. being trained
C. to have trained
D. to be trained
网友回答
A. training
B. being trained
C. to have trained
(答案→)D. to be trained
解析：不定式作目的状语，表示做某事的目的。不定式的被动式表示被动，根据he与train的关系可确定用不定式的被动式，表示“受训”。动词+ing形式的被动式的一般式表示这个被动的动作正在进行。选项A和C分别是动词+ing形式和不定式的完成式，都不表示被动，所以是错误的。