Fill in each blank with a suitable preposition.
1. Hoa's new skirt was white ___________ yellow flowers ___________ it.
2. Some young people are concerned ___________ the environment and work on neighborhood clean-up campaigns.
3. He was trying his T-shirt ___________ when his friend came in.
4. He finished his work ___________ less than 10 minutes before he came to visit his friends.
5. After finishing the task, please compare your answers ___________ your friends'.
6. Enjoying your food you eat is also the key ___________ a healthy lifestyle.
7. I have just received a letter ___________ my aunt in which she wrote a lot ___________ her and her family
8. Eating too much candy and staying up late too often are very bad ___________ your health.