Problem: George is investigating some algae that has recently started growing in his pond. He wants to find something ti prevent it from overtaking the pond as it makes it very hard to see under the water. After a bit of research he finds a protozoa that can help him. Given the protozoa can successfully reduce the algae in the pond, is it a herbivore or a carnivore?

A: herbivore

Problem: Two villages had many inhabitants practicing horticulture. People from Valley village grew flowers and used arthropods and other insects for pollination and crop protection. Granite village used arthropods and snails, they cultivated them for food. Which village used more butterflies and moths for pollination?

A: Valley

Problem: Two neighboring islands inhabited by thousands of birds each were hit by extreme weather. While Port island experienced wet weather over the past 3 summers, Bank island experienced severe drought, therefore the food supply on the island diminished. Which island had more birds with bigger beaks survive?

A: Bank

Problem: Douglas is an inventor who creates a miniature engine in his backyard that he uses to power his house. In order to fuel his engine, he has to burn a large amount of fossil fuels every day. His neighbor, Elijah, on the other hand powers his house through wind turbines, and in the process doesn't burn any fossil fuels at all. Who will contribute less to climate change?

A:
Elijah