Travelling in space has been made possible with the development of science and technology

问题补充：

Travelling in space has been made possible with the development of science and technology.

A. that

B. /

C. it

D. this

答案：

A. that

(答案→)B. /

C. it

D. this

解析：考查被动语态。本题是一个被动语态的形式，其主动形式为：With the development of science and technology, we have made travelling in space possible.随着科技的发展，我们让太空旅游变得可能。