竖井支护完成,并达到设计强度的后,方可施工横通道。
A. 50%
B. 60%
C. 70%
D. 100%
在长隧道施工时,为了缩短工期,要增设竖井、横通道以增加工作面
A. 对
B. 错
When did the two speakers last meet?
A. This weekend.
B. Three months ago.
C. Saturday evening.
D. Not mentioned.
What is the relationship between the two speakers?
A. Colleagues.
B. Competitors.
C. Business partners.
D. Classmates