They will have been married for 20 years by then.如果这句话换成一般将来时算错吗

Where have they been? They will have been married for 20 years by then.这里的been 表示什么 They have never been there __.A .and never will B.and never will goC.and will never have been D.and will never go there By this time next year,they ______ for sixty years.A) will have been marriedB) will have marriedC) will be marriedD) have been married Tom with his parents_____to America.They _____back in two weeksA.have gone;will come Bhas gone;will come C have been;have come D have been;come They will have been married for 20 years by then.可以换成They will have been marring for 20 years by then吗? where are the Greens?Well,they ---- to England.they have been there for nearly a weekA have been ;B are going ;C have gone;D will go These foreigners have been to Tibet before.--Really?When__here?A.will they goThese foreigners have been to Tibet before.--Really?When__here?A.will they go B.did they go C.have they gone these workers have been to English.when_there A.will they go B.did they go C.do they go D.have they gone They have a____ been there 英语?They will have been married for 20 years by then.请问been在句中作什么成份, who will have been to NO,I am sorry.They have not been typed yet,but they will be typed this afternoon. 薄冰：They will have been married for 20 years by then.到那时他们结婚将有二十年了.1:will have been+过去分词是什么结构?2:为什么不是 will have married3:为什么使用by 4:为什么使用for By the end of next year,they three modern hotels there--------By the end of next year,they three modern hotels there-----A、will built B、will be buildingC、will have been built D、will have built 英语改错!I have been to china last week they will very trouble in the cityi have been to china last week.they will very trouble in the city前面没分开了 - - They will have been married for 20 years by then.如果这句话换成一般将来时算错吗 ---Where are the Grees,may I ask?---Well,they ________to England.They have been there for nearly a week now.A.have been B.are going C.have gone D.will go为什么