If he had been looking where he was going.looking 后为何不加at

Stave said that if he had known how it worked,he would have been told If he had been looking where he was going.looking 后为何不加at He is talking so much about America as if he(had been)there.为什么不用has been? She treated him as if he (were/had been) a stranger. acted as if he had never been abroad before.句子成分怎样划分? my boyfriend looked as if he had been ill for a long time翻译 Jimmy would not have been stopped if he had gone down a side street. he had been reduced.he had been reduced 啥意思 He looked at me as if I were mad. 后半句是不是应该用 as if I had been mad啊? He would have given you more help,if he ______ (not be) so busy.是填 had not been吗? 英语翻译“He went into the forest,and he saw one standing there by six trees which he had rooted up as if they had been stalks of corn.” ___to the doctor right away,he might have been alive.A.If he went B.Were he gone C.Should he have gone D.Had he gone If there had not been 改成 had not there been 是had not there been 还是had there not been? 5.He looked as if he _____ ill for a long time A.was　　 B.Were C.has been　　 D.had been He is talking so much about America as if he ___ there.A.had been B.has been C.was D.were为什么选A不选B? he talks as if he ___ abroad before .A had really been B has really been C is really D was really he speaks Chinese as fluently as if he __a Chinese A were B had been C is D has been 求详解, 5.he speaks Chinese as fluently as if he() a Chinese.A.were B.had been C.is D.has been 选什么?是虚拟语气么?为什么?