Question

1. A hippo is an animal which has a big mouth.

2. A hippo is an animal which is very heavy.

3. A hippo is an animal which is very big.

4. A crocodile is an animal which has lots of teeth.

5. A crocodile is an animal which has a strog and long tail.

6. A crocodile is an animal which has scary teeth.

7. A turtle is an animal which cannot run fast.

8. A turtle is an animal which moves very slowly.

9. A turtle is an animal which has a hard shell.
===========================
Would you check the sentences? Correct errors, please. Thank you.

Answer 1

If you correct the spelling to "strong" in #5, all will be correct!

#5 would be better if it were phrased like this:
<i>A crocodile is an animal which has a long, strong tail.
</i>

Answer 2

1A. 2B