The human embryo goes through a stage where it has gills and a tail, similar to a fish. Where do the gills go as the embryo develops?

The "gills" and "tail" disappear before birth. Simple

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint