Which of the following is not true concerning cover crops?
a.
they prevent soil erosion
b.
they can fix nitrogen in soil
c.
they are sold as cash crops
d.
they add organic matter to soil

In which situations is the principle of cross-cutting relationship useful in determining relative age?

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity hurry!

Which of the following best describes the expensive tissue hypothesis? brains require more energy, so the gut had to be reduced, and larger brains and tool use led to higher quality diets. increasing body size means that homo neanderthalensis had to include more fat in its diet. brains require more energy, so the gut had to be reduced as brains got bigger. brains require more fat, so the gastrointestinal viscera (gut) had to expand, and hands were needed to acquire more food.