upgrade

/ˈəpˈgreɪd/

an upward slope or grade (as in a road)

中文释义：升级；提高

The government plans to upgrade the old railway system to improve efficiency.

政府计划升级旧铁路系统以提高效率。

Many people choose to upgrade their smartphones every two years.

许多人选择每两年升级一次智能手机。