Comma or Semicolon

I knew school supply shopping would be tiring but I didn't know I'd have to stand in line so long.

The dog growling and snapping ran right at me.

The suspect claimed he never met the victim however, the detective knew he was lying.

Riding a bike is excellent exercise I ride mine every day.

Millie has given up chocolate about five times but she cannot seem to break the habit.

Our cat has a built-in alarm clock he wakes us up at 5am every

morning.

I had to complete the assignment by Friday otherwise, I would have failed the class.

We always go to the mountains in the fall the trees are at their prettiest at that time of year.

The mayor pledged to cut taxes and the town responded enthusiastically.

I have read Macbeth but I have not read Othello.