the money will be used to keep a space vehicle on the moon busy ( ) back to the earth photographs and other information about the surface of the moon.
A to send B being sent C to be sent D sending
答案是d。这道题结构是什么啊,我选对的,以为是be busy doing的结构
回来看看觉得不像嘛,没有be的啊
有没有人明白!