What about inviting Mary to our party?You’d better not. She prefers to be so far

问题补充：

--- What about inviting Mary to our party?

--- You’d better not. She prefers to be , so far as I know.

A. tested out

B. rung up

C. left alone

D. turned around

答案：

A. tested out

B. rung up

(答案→)C. left alone

D. turned around

解析：考查词组：test out 考验；ring up 打电话给；leave...alone在此题中意为“让……一个人待着”，符合语境。turn around 转向，回转。句意：--邀请玛丽参加我们的聚会怎样？--最好不要，据我所知，她宁愿一个人待着。选C。