计算,选择得数。 ( ) 1. What's seventeen plus fourteen? ( ) 2. What's nine plus twelve? ( ) 3. What's thirteen plus thirty-six? ( ) 4. What's forty-one plus fourteen? ( ) 5. What's twenty-five plus fifteen? A. Forty-nine. B. Fifty-five. C. Thirty-one. D. Forty. E. Twenty-one.