A：空气
B：液态氮
C：干冰
D：高锰酸钾
Dear Mum,
How are you?
I'm very well in Shanghai. It's a beautiful city. I like the place. And I made a new friend. Her name is Huanhuan. She's got long and black hair. She's got big eyes. She is tall and thin. She's clever. But she is a bit shy. She likes English best. And she works hard. She often helps me. I miss you. I will be back next month.
Love,
Belinda
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