She knew she must calm and still until the enemy went away from her hiding cave.

 She knew she must ______ calm and still until the enemy went away from her hiding cave.

A. become              B. feel                         C. keep                        D. turn 

试题答案

C语境：应对危境；关键词语：until指所修饰的动词延续到某时为止，以及系动词的用法。考点：系动词，延续性和非延续性。