Morley: This is a great bike ride. I'm glad you agreed to do it.
Dan: [Looking tired] I'm beginning to think I bit off more than I can chew.
Morley: Maybe it's because of that race. I should told you I used to be a bike messenger.
Dan: [Gets a flat tire] Hey, I got a flat. Let's pull over and change it.
Morley: I've got the spare tube. Did you remember to bring the pump?
Dan: I knew I forgot something.
★ coast (n.) 海岸
★ bike messenger 单车快递。messenger是‘送信者’
★ flat (n.,a.) 平的；泄了气的轮胎。‘爆胎’的固定用法是flat tire
★ pull over （车子）靠边停
★ spare (a.) 备用的。‘备胎’是spare tire。tube 是轮胎的‘内胎’
★ pump (n.) 打气筒