[解析]
B C
W:Wait a minute,I have an idea.Now that we're going to the same place,why don't we share a taxi?
M:But it's cheaper to take a bus.The taxi will cost about 130 dollars,but the bus will only cost seventy dollars.
W:That's true.But if we share a taxi then it will cost about 65 dollars each.Actually,it will cost less than seventy dollars each.
M:That's a good idea.Let's do that.