disappeared down a drain,down 放在这里什么含义?down做什么词性？我觉得是介词，disappeared under the drain。和under的关系差不多

disappeared down a drain,down 放在这里什么含义?down做什么词性？我觉得是介词，disappeared under the drain。和under的关系差不多 lots of trees were cut down and some kinds of trees () A.were disappeared B.disapeared 英语翻译can you tell me how long dinosaurs -------- on the earth before they---------?A had existed ; disappeared B had existed; were disappeared C have existed ; disappeared D have existed ;were disappeared I still stood there untill the plane ( ) in the sky.A. has disappeared B. disappeared C. had disappeared D. would disappeared 我觉得答案应该是B, 可参考答案是C.究竟应该选哪一个呢? I still stood there untill the plane ( ) in the sky.A.has disappeared B.disappeared C.had disappeared D.would disappeared 我觉得答案应该是B,可参考答案是C.究竟应该选哪一个呢? Disappeared According to a UN report,a number of animals and plants （ ）in the last 500 yearsA、has been disappeared B、has disappearedC、have been disappeared D、have disappeared为什么不选C Where is my bike?It was outside the house.It____!A disappears B is disaappeared C has disappeared D was disappeared They ___the man until he disappeared.A.saw B.watched C.noticed D.looked 为什么? Those days are ____ forever.A.gone B.disappeared C.leaving D.passing bywhy? 求几道英语单选题!1.---------dinosaurs suddenly disappeared still remains a mysteryA what B why C that D whether2-----------is even more important is that as the earth cooled down ,water began to appear on its surface .A that B which C who D w _______the plane.A.Flew down B.Down flew C.Down was flying D.Down flew .All her doubts vanished after she read the letter from Jimmy.(A) broke (B) decreased (C) disappeared (D) grew My dictionary has disappeared.who_have taken it?A.should B must C.could D.would 选什么 为什么 they ()the train until it disappeared in the distance.A.saw B.watched C.noticed D.observed They _______ the train until it disappeared in the distance.A.saw B.watched C.noticed D.realized （）from the clothes ,the dirt disappeared .A.Remove B.Removing C.Removed D.Being RemovedD项为什么不能选 Suddenly,a tall man driving a golden carriage _____ the girl and took her away,_____ into the woods.A． seizing; disappeared B． seized; disappeared C． seizing,disappearing D． seized,disappearing