泥岩基线
参考答案：
大段泥岩岩性稳定，在自然电位曲线上显示为一条电位不变的直线，称为泥岩基线。
On snowy days, you have to drive very ____ to avoid traffic accidents. [ ]
A. cautiously
B. neatly
C. smoothly
D. properly
掘地派运动
