have been和are being的区别是什么?have been built和are being built还有were building的区别是什么?

have been和are being的区别是什么?have been built和are being built还有were building的区别是什么? is being和are being的用法?还有being和been的用法,为何有时过去式还用being? all that can be eaten_____eaten upA.are being B.has been C.had been D.have been 为什么?为什么用三单的形式？ have been还是have been being? 有have been being done和have being done吗?是什么时态? being done,have been done和having done怎么分辨 having being done 和have been done 有什么区别 All that can be eaten _______ eaten up. A are being B has been C had been D have been 存在have been doing、have being doing、和have be doing吗? Now that you ____,what are you going to do?A are being returned B have been returbedC have been returnedD have returned Look!Some trees _____ by them.A.are planted B.are planting C.have been planting D.are being planD.are being planted have been 和 has been的区别 The world's supplies of copper...a,have been gradually being exhaustedb,have gradually exhaustedc,are gradually exhaustedd,are being gradually exhausted The country’s chief exports are coal,cars and cotton goods,cars ____ the most important of these.A) have been B) being C) are D) are being Why ________ the old block of flats _________ demolished next month?A.are…being B.is…being C.has…been D.have…been The old _____well looked after in that small village.A.are being B.have C.have been D.is beingReason~ This is the first time the students________to Hyde ParkA.have gone B.have been gone C.have been going D.are being gone have been和have gone的区别