8. Ozone, a special form of oxygen that screens out harmful ultraviolet rays, reaches high concentrations twelve miles above Earth, where it has long appeared that it was immune from human influence; we have now realized, though, that emissions of industrial chlorofluorocarbons deplete the ozone layer.
(A) has long appeared that it was immune from
(B) has long appeared to have been immune from
(C) has long appeared as being immune to
(D) had long appeared immune to
(E) had long appeared that it was immune to
答案 D
這題我用刪去法,去掉ABCE,最後選D
但我不瞭解為什麼 D選項答案要用 V+pp 這個動詞型態? 這樣跟前後動詞型態不會不配合嗎?