first major overhaul

基本解释

If you are considering a major room overhaul, first plan your colors on paper.
如果你在考虑主房间的装修，先在纸上写出你的色彩计划。
Atlantis was the first orbiter to undergo numerous modifications during a 10-month major overhaul in 1998.
亚特兰蒂斯是第一个在航天飞机经过10个月的多次修改，1998年大修。

"The rule we will be publishing today represents the first major overhaul of the format and content or prescribing information in 25 years, " said Dr. Janet Woodcock, deputy commissioner for operations.
FORBES: Magazine Article
What we've alternately known as the "Tube" throughout much of its development cycle is the first production device to run S60 5th Edition -- the fourth major overhaul of Nokia's ubiquitous smartphone platform since 2002 and the first to support fingers, styli, and high-res displays.
ENGADGET: The Nokia 5800 XpressMusic Mobile