According to the big bang theory, how long ago did the universe begin? 5 to 10 billion years ago 13 to 15 billion years ago 23 to 25 billion years ago 30 to 40 billion year ago

Why is planting a wide variety of plant species better than planting only one type? a) diversity is best for the environment. b) a wide variety would mean less wear and tear on the soil. c) it would lead to desertification prevention. d) combining biological and chemical controls are the conditions of a healthy farm.