Over the last 6 months on A2K you' ve asked quite a few of these same sort of questions wanting corrections to vocabulary and grammar homework.
More importantly, you have repeatedly ask to actually do your son's work for him. That is not within the purvey of this site and most people here will ignore such requests.
The easiest and most efficient way to help him is to redirect you and him
to the online applications that exist specifically for that purpose.
The solution to helping your son is quite simple and well-known by even the most seldom users of Internet. There are dozens of online dictionaries where he can find the answers in 10 seconds or less to each definition well as grammar and usage issues.
While there are dozens, here are 2 such info resources:
Rogets Thesaurus http://www.roget.org/
Merriam -Webster dictionary http://www.dictionary.com/browse/merriam