试题题干
Translate the following sentence into Chinese.
Vitamins B and C cannot be retained in the body so if we take more than we need of these they are soon excreted in the urine.
参考答案
试题解析
考点：be retained in 保留在···；be excreted in the urine 从尿液中排出。
句子结构：句子为so连接的并列句。前半句为一个被动句。后半句主干为they are soon excreted in the urine，if引导条件状语从句。