掘进迎头生产过程中发生透水事故时，立即将所有人员从迎头撤至安全地点。
参考答案：对
The ties are good in both quality and style; she thinks that__________ she chooses will match her
boyfriend.[ ]
A. however
B. what
C. whichever
D. whatever
聚合物的粘性流动有何特点？为什么？
