1.Five hundred yuan a month（）enough to live on

1.Five hundred yuan a month（）enough to live on
A.is
B.are
C.is being
D.has been
2.（）of the buildings were ruined
A.Three fourth B.Three four
C.Three-fourths
D.Three-four
3.Consult （）for questions about earthquakes
A.the six index B.index six
C.sixth index
D.index numbering six
11.She went to the countryside ()
A.in the morning at nine on June first ,1968
B.on June first ,1968 in the morning at nine
C.at nine in the morning on June first ,1968
D.on June first ,1968 at nine in the morning
12.Three-fourths of the surface of the earth () covered with water
A.are
B.is
C.were
D.be
13.This month the production of stainless steel in our steelworks has increased () 2,000 tons
A.with
B.in
C.on
D.by
14.With the miniaturization of the structural components the weight of these electric devices has decreased () 30 percent
A.as
B.with
C.in
D.by
15.The Olympic Games are held ()
A.every four years
B.every four year
C.every fourth years
D.every four-years