Question

microbes that live in shallow lakes and ponds produce methane, a harmful greenhouse gas. ecologist ralf aben and his team wanted to see how different types of shallow - water plants might affect the amount of methane that escapes into the atmosphere. abens team set up some water tanks with soil and microbes from local ponds. some tanks had a type of underwater plant that grows in the soil called watermilfoil. other tanks had either duckweed, a type of plant that floats on the waters surface, or algae. aben and his team found that tanks with duckweed and algae released higher levels of methane than tanks with watermilfoil did. this finding suggests that
which choice most logically completes the text?
choose 1 answer
shallow lakes and ponds are more likely to contain algae than to contain either watermilfoil or duckweed.
shallow lakes and ponds release more methane than deeper bodies of water because shallow bodies of water usually have more plants than deep bodies of water do.
the presence of some kinds of underwater plants like watermilfoil helps prevent methane from escaping shallow lakes and ponds.
having a mix of algae, underwater plants, and floating plants is the best way to reduce the amount of methane in shallow lakes and ponds.

Explanation:

The text is about an experiment on how different shallow - water plants affect methane escape. Tanks with duckweed and algae (not underwater plants like watermilfoil) released more methane. So, the presence of underwater plants like watermilfoil likely prevents methane escape.

• Option A: The experiment is about methane release, not about which plants are more likely to be in lakes.
• Option B: The experiment does not compare shallow and deep water bodies.
• Option C: Since tanks with watermilfoil (an underwater plant) had less methane release, this option is logical.
• Option D: The experiment did not test a mix of plants; it tested different single - plant types.

Answer:

C. the presence of some kinds of underwater plants like watermilfoil helps prevent methane from escaping shallow lakes and ponds.