问题
选择题
The process of producing electricity may also give out CO2, ______ you heat your house with electricity instead of charcoal.
A．as long as
B．as soon as
C．as if
D．even if
答案
答案：D
考查短语辨析。句意为：产生电的过程也会发出二氧化碳，即使你用电而不是用木炭加热你的屋子。故答案为D。