阅读短信，选择方框所提供的单词使信的内容完整、正确。

Dear Jane,

    Thank you ____ your letter. I am fine. And how are you? I am 12 years ____. I am happy today because it's March 8th, it's ____ Day. I want to buy a pair of trousers for ____mother. She is busy every day, and I want ____ “Thank you” to my mother, too. Mr. Hot Clothes Store is near my home. Many clothes are on ____. They have green trousers for only $20. My mother likes green, but my father ____. He ____blue looks nice. Do you like sports? I like playing sports, I want to be ____.

What ____ you? I want to know you and be your friend.

Tommy

①请在如图所示的网格平面内作出平面直角坐标系；②请作出△ABC关于y轴对称的△A′B′C′；③写出点B′的坐标．