单选题
What fractional part of the total surface area of cube C is red?
(1)Each of 3 faces of c is exactly
(1)Each of 3 faces of c is exactly
【正确答案】
C
【答案解析】[解析] (1)不充分，因为无法判断另3个面的具体情况；(2)同理也不充分；(1)+(2)充分，根据此条件可以求出红色所占的比例为：
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