Is this sentence correct?

Happy New Year!

It's already Year 2008 .

My first question this new year is as follows...

Are the sentences below correct?

1. I go to work by car, by train or on foot depending on the weather.


2. You can't come to school by car, by bike or by motorbike. You have to walk here!


I'm not sure if I should repeat \"by\", or I shouldn't.

thank you!

hlzhou66

You should repeat"by".
It can't be omitted.
Because it is the fixed use for these vehicles