A(n) is a bend in a steep narrow bedrock valley. 2. The lowest level to which a stream can erode is called . 3. A(n) is the remnant of a former floodplain. 4. Examples of local base level include a stream or a(n) . 5. A sweeping bend of a stream which is migrating laterally in a wide, flat valley is called a(n) . 6. The flat, broad area surrounding a stream is referred to as a(n)