1、go by 后面不接since,用pass的话要用had passed2、which只能代指人或物,而what才能代指事件,这边是do sth.所以要用what
1. 如果选A & B,那么后面部分就只能是since he had left his hometown,所以只选C2.这个就考到了一个固定搭配了,例如,我会竭尽所能地去帮你,I will do what I can do to help you, do what sb. can do 就是竭尽所能的意思