单选题 It was not until then that I came to realize that knowledge from practice.
A. comes B. has come C. came D. had come

【正确答案】 A
【答案解析】直到那时我才意识到知识来源于实践。that引导的宾语从句表示的是客观真理，因此时态不受主句影响，用一般现在时。