Soaring television costs accounted for more than half the spending in the presidential campaign of 1992, a greater proportion than it was in any previous election.
Soaring television costs accounted for more than half the spending in the presidential campaign of 1992, a greater proportion than it was in any previous election.
a greater proportion than it was
a greater proportion than
a greater proportion than they have been
which is greater than was so
which is greater than it has been
Answer: B
不同意B,认为than后面应该补全被比较的事物,所以应该选A。it 指代 the proportion,请大家指正