.WeinFrancenow,buttheflight.()A.are;putsoffB.were;wasputoffC.weretoarrive;putoffD.weretohavebeen;wasputoffOnceasatelliteintoorbitroundPluto,scientistswillbeabletofindagreatdeal.()A.wil

Question

.We _______ in France now,but the flight _______.( )
A.are; puts off B.were; was put off
C.were to arrive; put off D.were to have been; was put off
Once a satellite _______ into orbit round Pluto,scientists will be able to find a great deal.
( )
A.will be put B.has been put
C.would be put D.was put
The method of painting is known as _______ far back as the Song Dynasty.( )
A.to be used B.to have used
C.to have been using D.to have been used

Answer 1

1.D,好难选,看了半天.是虚拟语气,我们本该已经在法国了,但是航班被推迟了.
2.B,once从句一般表将来（和if一样）.
3.D,没多可解释的了.不好意思.