Thousands of trees_______ every day.A are cut down B are bing cut down C have been cut down D had been cut downThe bird _________ fly away yesterday.A let to B is let to C was let D was let toA black car_________ him by his uncle.A sent to B will sent to C was sent to D will be sent forMany new houses__________ for teachers since last year.A are building B built C have built D have been builtThe medicine________ cool, clean and try.A must keep B must be kept C must be carried D must be in The lost boy________ this early morning.A found B was founded C was found D had foundthe room on the bus ________.A is took B has been taken C are taken D taken(請(qǐng)簡(jiǎn)單寫一下原因，謝謝！！！！！！！！！）

熱心網(wǎng)友

B，現(xiàn)在分詞表示一直在進(jìn)行D，let make 等可以省to接動(dòng)詞的詞的被動(dòng)態(tài)要加to，結(jié)合語態(tài)排除a,bC，應(yīng)選被動(dòng)態(tài)，且send to固定搭配D，有since是完成時(shí)的標(biāo)志。要選被動(dòng)態(tài)B，keep有保存之意，但carry沒有，在結(jié)合被動(dòng)態(tài)即可C，found是find的過去式，founded是建立的意思 B，用完成式的被動(dòng)態(tài)表示過去發(fā)生的事對(duì)現(xiàn)在有影響

熱心網(wǎng)友

Thousands of trees__B_____ every day。每天成千上萬的樹正在被砍伐。A are cut down B are bing cut down C have been cut down D had been cut downThe bird ___D____ fly away yesterday。昨天被放走A let to B is let to C was let D was let toA black car_______C__ him by his uncle。是他叔叔送他的，已經(jīng)送給他了A sent to B will sent to C was sent to D will be sent forMany new houses_____D_____ for teachers since last year。從去年到現(xiàn)在，許多房子已經(jīng)被建了A are building B built C have built D have been builtThe medicine___B_____ cool, clean and try。這機(jī)器必須被保持···A must keep B must be kept C must be carried D must be in The lost boy____B____ this early morning。已經(jīng)被找到，如果D的話要have be foundA found B was founded C was found D had foundthe room on the bus ___B_____。到現(xiàn)在為止已經(jīng)被占有了A is took B has been taken C are taken D taken。

熱心網(wǎng)友

BDCDBCB每道題要結(jié)合相關(guān)語境，理解了句子要表達(dá)的含義，你自然可以輕松選出正確答案。