61) Statement I :
Portions of glacial troughs may exhibit remarkably flat floors.
Statement II :
The flat floor in a glacial trough is produced by uniform glacial erosion.
Explanation :
Glaciers cut distinctive U-shaped valleys with a flat floor and steep sides. These are an example of a glacial erosion landform.
Example: As the main glacier erodes deeper into the valley, the tributary is left higher up the steep sides of the glacier.