he doesn't think.可以
he doesn't think the assignment was hard at all.可以
he thinks the assignment was a piece of cake.可以
he thinks 也可以 不过加个 not在后面就不行了
he thinks the song is great.可以
he thinks not= 不行.千万不要这样用
he doesn't think.可以
he doesn't think the assignment was hard at all.可以
he thinks the assignment was a piece of cake.可以
he thinks 也可以 不过加个 not在后面就不行了
he thinks the song is great.可以
he thinks not= 不行.千万不要这样用