One of those
habits is smoking, which scientists said is the biggest determining factor in a
person's lifespan. 请问老师句中scientists
said理解为插入语,还是理解为从句的主语+谓语,然后which指代smoking作宾语从句的主语?谢谢老师
1. She returned back to the office.2. She replaced the book back on the shelf.请问:句中的 back 是否是多余的?因为 return / replace 和 back 意思重叠。此外,有 return back 或 return sth. back 这样的词组吗?用法是什么?