问题
填空题
- (A) 条件(1)充分，但条件(2)不充分．
- (B) 条件(2)充分，但条件(1)不充分．
- (C) 条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
- (D) 条件(1)充分，条件(2)也充分．
- (E) 条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．
There are 105 students taking history and/or mathematics. How many students are taking only mathematics
(1) Thirty students are taking history only.
(2) Fifty students are taking both history and mathematics.
答案
参考答案：C