单选题 ______ yourself with all the company guidelines by the end of the third day of training, as there will be a test on the final day.

(A) Familiarize
(B) Familiarizing
(C) To familiarize
(D) Familiar

【正确答案】 A

【答案解析】[理由] 原句句尾有连接词as(因为，=because)引导的状语从句，得知空格前应为一个主句，故空格中应置入动词原形Familiarize(使熟悉)以形成祈使句。
原句实等于：
(You should) familiarize yourself with all the company guidelines...
根据上述，(A)应为正选。