Extremely deferential毕恭毕敬;必恭必敬
Extremely wealthy富可敌国;腰缠万贯
Extremely hard难于登天
extremely dark极深
extremely light极浅;轻而薄的;极轻的
Extremely Rare奇怪的;非常稀罕的;极端罕见;极其罕见
Extremely Sparkling极致闪耀
extremely grateful非常感谢
ADV（副词） You use extremely in front of adjectives and adverbs to emphasize that the specified quality is present to a very great degree. 极端地; 极度地 [ADV adj/adv] [强调]
My mobile phone is extremely useful.
我的手机极为有用。