Why you are late for school?
你为什么上学迟到了?
Because my bike has broken on the way,and this is why I am late.
因为我的自行车在路上坏了,这就是为什么我迟到了.
Why don't you read English in the morning?
早上你为什么不读英语呢?
I did!That's why I could improve my English so much!
我读了!这才是我的英语为什么提高了这么多的原因!