A; Can I help you?
B; Yes,I want to buy a pair of pants
A; We have pants in all colors
which do you want?
B;I like the black one,how much is it
A; It's 150 yuan
B;Oh,it's much too dear
A;How about the blue one?It's only 90 yuan
B;Oh,it's good,too.I will take it.Here is the money
A;Thank you
B You are welcome