gmat语法求解释
Ozone,aspecialformofoxygenthatscreensoutharmfulultravioletrays,reacheshighconcentrationstwelvemilesaboveEarth,whereithaslongappearedthatitwasimmunefromhumaninfluence;wehavenowrealized,though,thatemissionsofindustrialchlorofluorocarbonsdepletetheozonelayer
.(A)haslongappearedthatitwasimmunefrom
(B)haslongappearedtohavebeenimmunefrom
(C)haslongappearedasbeingimmuneto
(D)hadlongappearedimmuneto
(E)hadlongappearedthatitwasimmuneto
为什么wordy啊?