improving a sentence

[diamondcutter]

We still haven’t explored our seas and oceans completely but here are some interesting sea animals.

Seals live in the sea and on land, like turtles, but they don’t lay eggs! They are mammals, so they have babies and feed them milk.
...

Source: Kid’s Box 6, CUP

I don’t think the first sentence is well-written. What do you think of my improvement as follows.

We still haven’t explored our seas and oceans completely but here are some interesting sea animals, which we have already known much.

 

[tedmc]

How about:

We still haven’t explored our seas and oceans completely but here are some interesting facts about sea animals.

 

[5jj]

which we have already known much.

That does not work at all.

 

[emsr2d2]

... here are some interesting sea animals, about which we [STRIKE]have[/STRIKE] already [STRIKE]known[/STRIKE] know [STRIKE]much[/STRIKE] a lot.

emsr2d2

 

[tedmc]

... here are some interesting sea animals, about which we already know a lot.

I would expect to see a list of sea animals following the above sentence.

 

[5jj]

I would expect to see a list of sea animals following the above sentence.

There is information about eight sea animals following that sentence here.

 

[5jj]

emsr2d2... here are some interesting sea animals, about which we have already known know much a lot.

I'd drop the comma and make the relative clause defining.

 

[jutfrank]

I'd definitely put the preposition at the end in a text for such young learners:

... some interesting sea animals that we already know a lot about.