求助数学题目!

Is the measure of one of the interior angles of quadrilateral ABCD equal to 60 degrees?

(1)   Two of the interior angles of ABCD are right angles.

(2) The degree measure of angle ABC is twice the degree measure of angle BCD.

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.

                                                                                                  Answer:c

我选的是D，答案怎么是C呢？

(1)和(2)一个能说明不 equal to 60 degrees，另一个说明能 equal to 60 degrees。两个不是都对么！？

(1)正好能证明不存在60degrees,（2）能证明60degrees存在。

两边不是都能说明问题么？

饿~坍台了~把题目看错了，我当平行四边形做了。。。

真是太谢谢你了，解答了我两道题目~