is !X!+!X-1!=1 ? !代表绝对值符号，因为打不出来。。 (1) x >=0 (2) x <=1 A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. D. EACH statement ALONE is sufficient. E. Statements (1) and (2) TOGETHER are NOT sufficient.
答案C
但C能推出 !X!+!X-1!=2X-1，这个值可能为1可能不为1啊（X=1） 为什么不选E？ 谢谢！ !X!+!X-1!=2X-1，这个值可能为1可能不为1啊（X=1） 为什么不选E？ 谢谢！ | 
