Dachuan and Sun Dawei are walking through the campus when they notice a bike coming at them. Sun Dawei is not able to get out of the way and is knocked over.
xiǎo xīn kuài ràng kāi
小 心！ 快 让 开！
Take care. Hurry up and keep off！
duì bù qǐ wǒ de chē zhá huài le
对 不 起，我 的 车 闸 坏 了。
Sorry. The brake on my bike is broken.
méi guān xi qí chē bié qí tài kuài le
没 关 系，骑 车 别 骑 太 快 了！
No problem. Don't ride a bike so quickly!
hǎo de shí zài hěn bào qiàn
好 的， 实 在 很 抱 歉！
Ok. I'm very sorry.Dialogue Two
nín zěn me le
您 怎 么 了?
What's wrong with you?
méi shén me gāng cái chōu le liǎng zhī yān
没 什 么， 刚 才 抽 了 两 支 烟，
yǒu diǎnr ké sou
有 点儿 咳 嗽。
Nothing. I just coughed because I smoked some cigarettes.
nín bié chōu yān le duì shēn tǐ bù hǎo
您 别 抽 烟 了，对 身 体 不 好。
Please don't smoke. It's not good for your health.
xiè xie wǒ jǐn liàng shǎo chōu diǎnr
谢 谢， 我 尽 量 少 抽 点儿。
Thanks. I'll smoke as little as possible.
Explanation of difficult points
"快让开！" (kuài ràng kāi) means "make way" or "stay out of the way". The "开" (kāi) in "让开" (ràng kāi) has yet another meaning than previously used. In this case, it means "away".
"来不及" (lái bù jí) means there is not enough time to do something. "来不及" has the same meaning as "没来得及" (méi lái de jí).
"别" (bié) + verb means "don't do something".
The "了" (le) at the end of the "别骑太快了"(bié qí tài kuài le) softens the tone to be suggestive rather than demanding.
"……对……不好" (duì bù hǎo) means "(something/doing something) is not good for (something)."