题干
So far we have done a lot to build a low—carbon economy, but it is ____ideal. We have to work still harder.
A：far from
B：next to
C：out of
D：due to
答案(点此获取答案解析）
A
是
的充要条件. 
的充要条件. 
的充要条件.则其中正确的说法有（ ）
