根据对话内容，用适当的单词或句子补全对话。

A: Good morning, madam. ?

B: I'd like a T-shirt for my son

A: What size does your son  ?

B: Size L. He is a tall boy. He loves cotton T-shirts.

A: What this one? It's made in China.

B: OK. Let me have a look.  is it?

A: 120 yuan. It's popular now.

B: But I'm afraid it's a little more expensive and I don't like the color.

A: Do you like the black one? It's only 100 yuan.

B: Hmm, it looks nice. I'll it. Thank you.

A: You're welcome.