The Wankel rotary engine was an engineering marvel that (i)_____ automobile exhaust emissions, but because it was less fuel efficient than the standard piston-cylinder engine, it was (ii)_____ in the early 1970s when (iii)_____ pollution gave way to panic over fuel shortages.
Blank(i)
Blank(ii)
Blank(iii)
A、depended totally on
D、necessitated
G、ignorance of
B、preceded the problems with
E、conceived
H、espousal of
C、substantially reduced
F、abandoned
I、preoccupation with
答案：substantially reduced,abandoned,preoccupation with