You have been asked to write an essay about the layers of a rainforest ecosystem. Which of these is the most effective topic
sentence for a paragraph in this essay?
Rainforests are one of Earth's most precious ecosystems.
O The emergent layer of the rainforest ecosystem gets the most sunlight.
O The rainforest is full of life at every layer of its ecosystem.
O There are four layers in a rainforest ecosystem: emergent, canopy, understory, and forest floor.