Please help im being timed The causes of climate change can be divided into two categories: natural and human causes. The natural variation of the climate has always been part of Earth’s history. It is now a great concern that the climatic changes occurring today may be the direct result of man's activities.

All BUT ONE is a natural cause of climate change.
A) ocean currents
B) volcanic eruptions
C) Earth's orbital changes
D) increased greenhouse gases

Which of the following is a macronutrient? carbohydrates lipids amino acids all of the above

Human genes only differ by less than percent. a. 1 b. 6 c. 11 d. 16

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.