题目

The teacher raised his voice , but still couldn’t make himslf _________. A. heard        B. hearing     C. to be heard       D. hear 答案：A 解析: 略6．现在有2吨货物，第一次运走$\frac{3}{10}$吨，第二次运走$\frac{7}{15}$吨，两次一共运走多少吨？还剩多少吨货物？