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