What role did charles darwin play in evolutionary theory?

What is the difference between bacterial infections and viral infections?

Which of the following is not a symptom of desertification? a) decrease in salt content of the soil b) lowering of the water table c) reduced surface water d) increased soil erosion e) loss of native vegetation

Label the following as inner or outer planets; a) has 67 moons made mostly of hydrogen and helium b) has rings c)no moons, high volcanic activity d) known as the red planet, has 2 moons e) very thin atmosphere, moons or rings