The tour guide, who has become a good friend, is great!
Explanation:
The commas help separate the two ideas in one sentence correctly. A good way to check that this is correct is to remove the words separated by the commas - "who has become a good friend" - and check if the sentence still makes sense. In this case it would be "The tour guide is great!" which makes sense as a sentence. Thus, this version of the sentence is correct.
becausethe tadpoles starts to lose its gills and develop teeth. Soon after this their back legs develop, their diet changes and they become carnivorous
