It's up in the air.尚未确定。

up in the air是习惯说法,指计划、问题等悬而未决，尚未确定。

SCENE 1

Ann: When are you going to Australia?

你打算什么时候去澳洲?

Jesse: It's up in the air.

尚未确定。

SCENE 2

Mason: Have you bought the new house?

你买了新房吗?

Mary: No,we have many choices but we can't decide which is best. So,it's up in the air.

还没呢。我们有太多的选择，以至无法肯定哪一套最合适，所以还没定下来。

SENTENCES

1、My plan for studying abroad is still up in the air.

我出国学习的计划还定不下来。

2、The design of this building is still up in the air.

这栋楼的设计还没定下来呢。

3、John's marriage is still up in the air.

约翰的婚姻问题尚无着落。