1. Biological control is the intentional manipulation of natural enemies by humans for the purpose of controlling pests.
2. Mechanical control includes mowing, hoeing, cultivation, and hand pulling.
3. Chemical control is the use of herbicides.
Answer:
A. It is a source of genetic variation
D is the answer to the problem
An irregularly occurring and complex series of climatic changes affecting the equatorial pacific region and beyond every few years, characterized by the appearance of unusually warm, nutrient-poor water off northern Peru and Ecuador, typically in late December
