题目

senior high school English
1.什么情况用have什么情况用have been?
a lot of factories____
have been set up对 have set up错
set up 好像是点动词词组吧.怎能用been?
2.their duty is to__their country against foreign enemies's attacks.
A defeat B defend 咋选B
3.Coal was formed out of dead forests by chemical__.
A processes B product 咋选A

提问时间：2020-07-18

答案

factories与set up 构成谓宾关系
意思就是 要用被动语态
完成时的被动语态就是have/has been done
不能完全靠中文意思来理解的
defeat击败,战胜；使…失败；挫败的意思
defend防护；辩护 保护的意思
可以从意思上理解
还有就是 defeat 不与against连用的
processes复数时是加工；处理的意思（process的第三人称单数形式）
chemical process指特定的化学反应过程
chemical product指化学产品