Descriptive text overpass

1, followed by: logic, progression, structure, shape, function, development 2, center (sentence) 3. The explanation method of column number is also used to accurately explain the great role of overpass in urban economic and social benefits. It cannot be deleted. Because "basic" refers to the main and common types of overpasses, if removed, it will become the only type of overpasses, which is inconsistent with the facts and inaccurate.