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 答案给的是C,我怎么看都觉得应该是B