Dan outfitted his house to run on the oldest heat source on Earth. What is the oldest heat source on Earth?
Options:
- fire
- solar energy
- sun
- house
- coal or wood
Let's do it gradually: Solar energy is the energy that is collected from the heat of sunlight. Sun is the centre of the galaxy in which earth is present. Sun is older than the earth.... So the answer is solar energy.

Where would bacteria be contained?
Options:
- finger
- ground
- septic tank
- mouth
- petri dish
Let's do it gradually: Septic tank is a large container to store water. Something stored in a container stays contained.... So the answer is septic tank.

When a main artery is used to expedite travel what would it be referred to as?
Options:
- neck
- busy city
- own brain
- thruway
- food

Let's do it gradually: While travelling, artery means high ways that can speeden the travel. This highway is also known as thruways as they cut the distance.... So the answer is thruway.