Select the main differences between primary and secondary succession. There are no differences. The main difference is the primary succession occurs after killing all life and soil, and the secondary succession happens where no life or soil was before. The main difference is the primary succession occurs where no life or soil was before, and secondary succession happens when there is already life and soil. The main difference is the primary succession occurs when there is already life and soil, and secondary succession happens where no life or soil was before.
