问题 选择题 给下列的算式选择正确的答案。( ) 1. 41 －19 + 5 =( ) 2. 18 + 8 + 7 =( ) 3. 32 + 9 －10 =( ) 4. 50 －6 + 15 = A. thirty-oneB. thirty-threeC. fifty-nineD. twenty-seven 答案 1. D 2. B 3. A 4. C
