How to put these in a compound sentence?

Simple-Dolphins are very intelligent, social creatures.

Simple-Katy is thinking she might like to become a marine biologist one day

3 answers

A compound sentence has two independent clauses.

Study this site.

http://www.eslbee.com/sentences.htm

I'll be glad to check your sentences.
can you at least start the second one for me please
Katy is thinking she might like to become a marine biologist one day

Katy is thinking she might like to become a marine biologist, but she's also interested in veterinary science.