题目内容：
10. Building that railway was very difficult and involved _____ ten tunnels.A. dig
B. throwing
C. to have thrown
D. having thrown
参考答案：
选择题：10. Building that railway was very difficult and i
- 题目分类：河北建筑工程学院-建筑工程技术（专科）-大学英语1
- 题目类型：选择题
- 查看权限：VIP
A. dig
B. throwing
C. to have thrown
D. having thrown