英语翻译 NOW!

It's not sure that how long it will take the human beings to living in the bottom of the sea.

为什么用in 而不用at 因为，这里中文意思并不是说人类真正地住在海的最底层，而是在海洋中生活。

Human beings are not sure when they will be able to live at the bottom of the sea.

It is not certain yet how long after that humann being can live under the sea.

人类要多久才能生活在海底尚没有把握。
Human beings are still not sure how long they will wait to live at the bottom of the sea.

it's still not sure about how long people can live under the ocean.

How long would it take to human life in the seabed is still no certainty