American scientists Stanley Miller and Harold Urey used an apparatus similar to the one in the diagram below to simulate how life could have formed on Earth. The apparatus contained hydrogen gas, water vapor, ammonia, and methane. These gases were subjected to a spark, to simulate lightning. They found that organic molecules could form from the inorganic gases. Their theory of how life began, however, did not hold up under further testing. What crucial fact did they not have when they conducted their experiment?

F. There was no lightning in Earth's early atmosphere.

G. Ammonia and methane were not in the early atmosphere.

H. The chemicals used in the experiment were contaminated.

I. Organic molecules already existed before the atmosphere formed.

Ascientist and her team counted 200 individual deer in an area of 10 square kilometers. what is the population density?

Benito is doing research on the effects of florida's elevation on its climate. his notes include the following: 1. the average elevation of florida is 30 m above sea level. 2. the highest point in florida is britton hill, which is 105 m above sea level. 3. the change in temperature from 0 m to 1,000 m is 7 °c. what can benito conclude about the effects of florida's elevation on its climate? a.) florida typically experiences cold temperatures and temperature changes within a narrow range. b.) florida typically experiences cold temperatures and temperature changes within a broad range. c.) florida typically experiences warm temperatures and temperature changes within a narrow range. d.) florida typically experiences warm temperatures and temperature changes within a broad range.

Which ocean is on the eastern coast of north and south america? arctic ocean indian ocean pacific ocean atlantic ocean