个 2.3.4 Quiz: Weather and Climate Question 2 of 10 Which of the following is true of high clouds? O A. They cause most precipitation. B. They are composed of ice crystals. C. They generally produce lightning. D. They are a sign of severe weather.

Which of the following statements is accurate about evolution? question 10 options: natural selection only eliminates odd individuals. evolution means that a population never has changes in its genetic frequencies. mutations are always harmful. evolution means that a population undergoes changes in its gene frequencies over time.