You are presented with the quiz "Flowing water can slowly dissolve carbon in what?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "flowing water can slowly dissolve carbon in sedimentary rock" and "sedimentary Rocks One of the commonest sedimentary rocks is sandstone". So, what's the best answer to the question?

OPTIONS:
- oil
- water
- crust
- ice
- loose dirt
- sandstone
- precipitation
- loose soil

Answer: sandstone

You are presented with the quiz "what can some viruses cause?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "some viruses can cause cancer" and "leukemias are cancers of the blood". So, what's the best answer to the question?

OPTIONS:
- extinction
- anemia
- wounds
- leukemia
- Allergies
- loss of gravity
- Dehydration
- virus protection

Answer: leukemia

You are presented with the quiz "what does methane produce when burned?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "biofuel is used to produce electricity by burning" and "biofuels include ethanol, methanol, biodiesel, biocrude, and methane". So, what's the best answer to the question?

OPTIONS:
- carbon dioxide
- energy
- electricity
- The atmosphere
- heat energy
- adding heat
- It expands
- kinetic energy

Answer: electricity

You are presented with the quiz "what have jointed segmented exoskeletons?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "most arthropods are insects" and "arthropods Arthropods have jointed segmented exoskeletons". So, what's the best answer to the question?

OPTIONS:
- insects
- mountains
- tortoises
- barnacles
- humans
- crocodiles
- knee joints
- animals

Answer:
insects