Astronomers and scientists think that a black hole is a region of space which matter has

问题补充：

Astronomers and scientists think that a black hole is a region of space which matter has fallen and which nothing can escape.

A. into; from

B. towards; towards

C. out of; from

D. through; through

答案：

(答案→)A. into; from

B. towards; towards

C. out of; from

D. through; through

解析：考察定语从句中的介词。本题定语从句的先行词是a region of space。第一空中的介词into是由动词短语fall into…转换而来；第二空的from是有动词短语escape from…转换而来。句意：宇航员和科学家认为黑洞是太空中的一个区域，物质进入了那个区域以后就什么也逃脱不出来了。故A正确。