Place commas where it is needed.
1. we welcomed the warm morning sun after a cold sleepless night in the tent.

2. you’ll get good life out of your tires as long as you check the air pressure at least once a month have them rotated and balanced every five thousand miles and get the alignment checked yearly.

3. night classes which are the only practical alternative for people who hold full-time jobs can be more demanding than day classes.

4. lisa was having trouble with her car and took it to a mechanic but he couldn’t find anything wrong.