问题
选择题
It’s suggested that everyone should_______ at least one hour a day to keep fit.
A．work for
B．work out
C．work at
D．work on
答案
答案：B
考查短语辨析。work for 为了什么工作， work out 算出，锻炼身体，work at 在上班，work on 从事，句意：据建议每个人应该一天至少锻炼一小时来保持健康。所以选B。