Employment costs rose 2.8 percent in the 12 months that ended in September, slightly less than they did in the year that ended in the previous quarter.
Employment costs rose 2.8 percent in the 12 months that ended in September, slightly less than they did in the year that ended in the previous quarter.
(A) less than they did
(B) less than it did
(C) less than they were
(D) lower than
(E) lower than they were 答案是A。 不懂为什么。我选的是C。 望各路NN们帮我答疑解惑啊, 在此先谢谢各位!