You'd better go to work __ __every day if you want to keep__.如果你想保持健康,最好每天步行去上班．3空

You'd better go to work __ __every day if you want to keep__.如果你想保持健康,最好每天步行去上班．3空
You'd better go to work __ __every day if you want to keep__.
如果你想保持健康,最好每天步行去上班．
3空

You'd better go to work __ __every day if you want to keep__.如果你想保持健康,最好每天步行去上班．3空
on foot
healthy

You'd better go to work by foot every day if you want to keep fit.
keep fit
保持健康