To those scientists, it still remains to be a question ______ man can go back to the old days with time machine

Mark speaks English well, but you______________ him.—Thank you.

I acquired ______ Van Gogh from a businessman from Paris the other day.—Really Are you sure it’s ______ real one

green grass , which live in perfect harmony with people there.

依次填入下面横线处的语句，最恰当的一组是（ ）陶潜和阮籍在魏晋时代分别创造了两种迥然不同的艺术境界： ， ； ， 。 。应该说，不是建安七子，不是何晏、王弼，不是刘琨郭璞，不是二王、颜、谢，而是他们两个人，才真正是魏晋风度的最优秀代表。①他们以深刻的形态表现了魏晋风度。②慷慨任气 ③一是忧愤无端 ④ 冲淡平和 ⑤一是超然事外