[单选题]
在线路允许速度 160≥Vmax>120km/h正线,线路轨道静态几何尺寸容许偏差管理值中,三角坑(缓和曲线)的临时补修标准为( )mm。
A.5
B.6
C.8
D.3

Now we travel to the north central part of the United States. We are in the state of South Dakota. The land is big and mostly fiat with many{{U}} (36) {{/U}}of com, wheat and soybeans. But as we travel west, the cropland gives way to wild grasses. A strong dry wind blows{{U}} (37) {{/U}}from the west.
Suddenly, the land’ becomes{{U}} (38) {{/U}}and rocky, dry and dusty—no longer green and gold. It is now a light red- brown color. All around arc broken{{U}} (39) {{/U}}forms. There are hills and valleys of all sizes and strange shapes.
These are the Badlands. Hundreds of thousands of years ago the area was{{U}} (40) {{/U}}, but, then, forces of nature{{U}} (41) {{/U}}the grass. Water and ice cut into the surface of the earth. They beat at the rocks,{{U}} (42) {{/U}}them away. The result is one of the world’s{{U}} (43) {{/U}}sights.
{{U}} (44) {{/U}}.
The area is a study in extremes. Temperatures in t