Before the first non-stop flight made in 1949, it ________ necessary for all planes to land for refueling.

A．) would be B) has been

C．) had been D) would have been

 

 

[试题]B．eforethefirstnon-stopflightmadein1949,it________necessaryforallplanestolandforrefueling.A．)wouldbeB)hasbeenC)hadbeenD)wouldhavebeen

[单选题]---What should I do first before boarding? ----().A．You may ask the policeman there to help.B．Please go to the airline counter to check-in for your flight.C．You should wait and see.D．You have to go there to check in for your flight.

[单选题]24．The Egyptians made the first balls with _________ ．A． animal skinB． something lightC． leaves and vinesD． paper

After we made the improvement; there were only ______ as before.A. one-tenth def

It was, for example, the first country to produce paper money. Before the invent

It was, for example, the first country to produce paper money. Before the invent

In the first test, each subject (试验对象) sat before a computer screen and pressed

Understandably Ann was so nervous.After all it was the first time that she ever

[单选题]A financial contract offers to pay €1,200 per month for five years with the

[单选题]A financial contract offers to pay (:1,200 per month for five years with th