He agreed to most of the plan,but was against starting it now.为何前面用was但后面可以用now?

问题描述:

He agreed to most of the plan,but was against starting it now.为何前面用was但后面可以用now?

他同意这个计划,但是不同意现在实施.
现在是指实施的时间,不是同意的时间,同意这个动作发生在过去.