had been studied和had studied有什么区别?还有请回答下面的问题^o^

来源：学生作业帮编辑：作业帮分类：英语作业时间：2024/05/17 02:25:53

had been studied和had studied有什么区别?还有请回答下面的问题^o^
Mr.Wu_______in America for two years.No wonder he can talk witn foreigners now at the office in China.为什么答案是“studied”而不是“had studied”

had been studied是被动语态,被研究.had studied是研究,表示主动.
至于下面的句子,后面说他现在可以和外国人交流,前面要用一般过去时,表示他曾经在美国学习了两年.不需要用过去完成时.
再问：那请问一下，have been doing是主动还是被动？

had been和have been有什么区别?请举例 if i studied harder和 if i had studied harder 语义上有何差别 If i had studied had gone和had been 有什么区别? had done 和 had been done有什么区别啊? 英语大神回答,have,had的区别和使用,还有什么情况用have had. 英语语法的一些问题has been explained 和 had been explained 它们两个有什么区别吗? has been和had been 有什么区别? 关于Have和Had 还有Have been和Had been的区别 have been 和had been 什么区别英语细节问题请教had been had gone had done的区别还有BE什么情况下会原形出现在句子中比如 was doing、had been doing和had been done都有什么区别?