23.The modern technology to shrink(缩短) the distances of runways which large and fast aircraft use.

23.The modern technology to shrink(缩短) the distances of runways which large and fast aircraft use.
a.has begun b.have begun
c.began d.had begun
12.Once you the brand of whisky,you will never want to drink any other.
a.drunk b.have drunk c.will drink d.drank
17.He was disappointed that all of the guests when he at the party.
a.left,had arrived b.left,arrived
c.had left,had arrived d.had left,arrived
18.How long you the army till now?
a.did,join b.have,joined
c.have,been d.have,served in
–Nancy is not coming tonight.
A.promises B.promised
C.will promise D.had promised
..为什么啊- -..