Ferns make their own food. They grow and reproduce using spores instead of things like seeds. Humans on the other hand have to ingest food from their surrounding and when mature reproduce sexually. They can also choose if they want to reproduce or not while ferns don't have that option. Sexual reproduction is based on inseminating and egg cell, while ferns don't worry about this because the spores just fall on the ground.
Answer:
do you mean a watering pot/can?
The answer is the option A. removing plants from hillsides eliminates the root structures that anchor soil. Indeed the roots of trees, further to anchor the tress to the floor, serve as a net to which the soil attaches preventing the soil of been washed and removed by rainstorms
The independent variable controls the dependent variables.