The following data sufficiency problems consist of a question and two statements, labeled (1) and (2), in which certain data are given. You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given in the statements plus your knowledge of mathematics and everyday facts (such as the number of days in July or the meaning of counterclockwise), you must indicate whether.
If 
is a positive integer, what is the value of r ？（）
(1) r＜70
(2) [*]
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.
参考答案：C
解析：
alone is insufficient because r could be several numbers less than 70, such as 64 or 49. (2) alone is insufficient because r could be several numbers greater than 49, such as 64 or 81. When the statements are combined, the only number that meets both criteria is 64, so the answer is C.