According to my hamble knowledge, it's generally OK. fficeffice" />

You can look up the following sentence in Official guide Page 696, Para 3:
"B replaces child with children but otherwise fails to correct A's errors of structure and logic, and C corrects only the error created by occurring."

我认为都可以. 分号的用法你可以在OG里找一下. 我考试时遇到一题. 两个句子, 前一个是一个事件, 也是后一句的原因. 选项中有用逗号连接两句的, 也有用分号. 分号的选项中, 后一句用therefore开始. 我的选择是带分号的. fficeffice" /> 根据OG, 两个分别有独立主谓结构的并列句子中间用and连接, and前必须有逗号. 没有必错.