填上正确的preposition.

Most of our guests arrived __by__car but my brother came_on_foot.
You shouldn't be__at__work with that awful cough,you should be__at__home,__in__bed.
I deleted your email __by___mistake,I didn't do it __on___purpose.
I usually travel___by__train when I go to scotland___on___business.
The movie star met her lover_in___secret because they didn't want to be seen together _in___public.
Every time I try to see the manager he's either__at___lunch or__on___-the phone.
They met__by__chance on a train and they've been___in__love very since.
If you're not____in___a hurry,we could go to the city centre_by___bike.