问题
选择题
Mr. Smith insists on doing some running even __ a cold morning.
A．in
B．on
C．of
D．at
答案
答案：B
搜题请搜索小程序“爱下问搜题”
Mr. Smith insists on doing some running even __ a cold morning.
A．in
B．on
C．of
D．at
答案：B