英文时态必须一致吗

问题描述:

英文时态必须一致吗
there was a widespread belief that the newspapers had not told the truth.----------一个 was过去式,一个had过去式,told也过去式,应该是时态一致了
可还有下面这个句子:
you were wise to give up smoking.------为什么不用gave呢?

从句是时态一致,但跟在to后面不是从句,to后一般用原形,第一句那是that,是从句