keep up with是什么意思?
问题描述：
keep up with是什么意思?
答
.跟上They walked so fast that I could not keep up with them.他们走得那么快,我没法跟上.2.和...保持联系She has kept up with some of her friends since her retirement.她退休后一直同一些朋友保持着联系....