Answer:
My teacher is an important woman. She works all week so that I can learn, get experience, and have interesting lessons to work on. She is always there to help me when I need it. She even stays late to decorate our classroom for birthday parties and brings us treats every Wednesday afternoon.
Explanation:
Look at the sentence CAREFULLY. See if you can spot where the sentence is supposed to end. If you hit a point where the sentence sounds wrong, try to trace back your steps to where it sounds right. It should be fine to add a period there. Does that make sense?