In the face of failure it is the most important to keep up good state of mind.A. /; aB.

问题补充：

In the face of failure, it is the most important to keep up good state of mind.

A. /; a

B. a; /

C. the; /

D. /; the

答案：

(答案→)A. /; a

B. a; /

C. the; /

D. /; the

解析：考查冠词。第一空中的failure抽象名词失败，单独使用；第二空泛指一个思想状态。句意：在面对失败的时候，保持健康的生活状态是很重要的。故A正确。