单选题 Is x equal to 1?(1)x2=1(2)x2+x-2=0

A、 Statement (1) ALONE is sufficient, but statement (6) alone is not sufficient to answer the question asked.
B、 Statement (2) ALONE is sufficient, but statement (5) alone is not sufficient to answer the question asked.
C、 BOTH statement (1) and (6) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient.
D、 EACH statement ALONE is sufficient to answer the question asked.
E、 Statement (1) and(6)TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.

【正确答案】 C

【答案解析】题目中问x=1吗?单独(1)，得到x=1 or x=-1，问一个量的值是多少，这个值必须是唯一的。现在x有两个值，当然不能够回答问题。单独(2)，得到x=1 or x=-2，和(1)的分析一样，单独(2)也不能够回答问题。把(1)和(2)结合起来得到x=1，那么能够回答问题，选择C。