我们不知道这个世界有没有外星人 用英语怎么说?
问题描述：
我们不知道这个世界有没有外星人 用英语怎么说?
答
We wonder whether there are any aliens in the world or not.
答
I don't know if there is alien exists in our world.
答
We're not sure whether there are aliens in this world.
答
we don't know whether there are aliens in the world or not
答
We don't know if there are aliens in the world.
答
We don't know whether there are extra-terrestrials in the world or not.
答
We don't know that this world is not alien