Can someone help me with this comma exercise?

Comma Exercise

Correct each sentence. Explain why you are using (or not using a comma). Correct other errors as you find them.

1. After completing its topographic survey of the area the crew returned to headquarters for the weekly project meeting.
2. The case against Senator Barton was fabricated so the judge dismissed it.
3. Jason opened the containers in a dry well-lighted place.
4. The colors red blue black white and silver are popular for cars today.
5. However it is interesting to see the crowds reaction to their leaders words.
6. I rescued a bird this morning, it was trapped in the building and could not find its way out.
7. That date therefore is very important to Jenny.
8. The commissioner postponed the baseball game so we have to find something else to do.
9. I wanted to go to Big Lots. Especially to look for bargains.
10. All marriage is a sort of gambling like blackjack or poker with a slight finality to it.

thank you for your help with this.