阅读下面日记，完成小题。
Saturday 29 May 
Something has changed my mind today. I saw some pictures of the sea animals influenced by the rubbish in the sea. I can't get that out of my mind. So, I am going to try and live a more environment-friendly life. (A)Each day I will keep trying to change one thing that I do to protect the earth.
Monday 31 May 
Today I have decided to stop using plastic wrap (塑料保鲜膜) around the sandwiches that my mom makes for my lunch. Plastic wrap keeps my sandwich nice and fresh, and it's easy to throw away. However, I come up with a better idea. I can use a glass container (容器) instead of the plastic wrap. So, I can reuse it the next day for lunch. And I told this to my classmates too. I hope to see more reusable containers at school tomorrow.
Thursday 3 June 
Good news, when I took out my glass container, I noticed more of my classmates bring their home-made lunch in their own containers to school! Tonight, when I was shopping with my mom, I found a shop which doesn't provide any plastic bags! The idea of the shop is that you bring your
own cloth bags. In this way, there are no plastic or paper bags to throw away at home. When I left the store with the buys in my own cloth bags, I felt very proud of myself. (B)Tomorrow I'm taking the bus to school to save energy.
Friday 4June
What a wonderful bus ride to school today! Well, it's been a week since I decided to try to live a more environment-friendly life. The unbelievable part is that I can actually see a difference in the garbage(垃圾) in my home. The garbage bag is lighter and only one third filled. I feel excited that I have made a real difference. I'm going to keep saving the world one day at a time.
Why did the writer decide to live a more environment-friendly life?