You have 10 acres of farmland to grow crops. What is the most energy efficient way to feed people with this land? A. Grow corn on half, and wheat on the other half, and use it to feed cows and pigs, and then eat the cows and pigs.
B. Grow corn to feed cows, and eat the cows.
C. Grow corn to feed chickens, and eat the chicken eggs.
D. Grow corn and eat the corn directly.

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.