Fred entered without knocking and, very out of breath, sank a chair.
A. on
B. off
C. into
D. to
网友回答
A. on
B. off
(答案→)C. into
D. to
解析：考查动词与介词的搭配。“sink into sth”意思是“渗入，陷入，沉入；投入……”等意思，“sink into a chair”意思是“（一屁股）坐到椅子上”。其它搭配均不恰当。
sink into…是一个非常有用的搭配，可与很多名词连用，表示多种意思，如sink into one’s mind（教训等）铭记在某人心中，sink into the sea沉入海中，sink into a deep sleep沉睡。