Having an outdoor meal is always fun, but it can also be damaging to the planet if .
A. planned not carefully
B. not planning carefully
C. not planned carefully
D. not to be planned carefully
网友回答
A. planned not carefully
B. not planning carefully
(答案→)C. not planned carefully
D. not to be planned carefully
解析：考查省略句。当状语从句的主语和主句的主语一致，且状语从句中有be动词的时候，可以把状语从句的主语和be动词一起省略。本题在if后面省略了it is。句意：出去吃饭也行有有趣。但是如果没有被仔细计划，它也可能回破坏我们的地球。故C正确。