Solar energy can produce enough ________ to heat or cool an entire house.

• powerless  

• powerfully  

• power  

• powerful

Our sources of energy will soon be___________ if we don’t save them.

• exhausting

• exhausted

• exhaust

• exhaustedly

The panda's ______ habitat is the bamboo forest.

• nature  

• natural

• naturalized

• naturally

The ______ friendly products are designed not to harm the natural environment.

• environment

• environmental

• environmentally

• environmentalism

The waste from the chemical factory is extremely ______.

• harm

• harmful

• unharmed

• harmless

Hunting for meal and burning forests for soil ___________ wildlife.

• protects 

• conserves

• destroys

• survives

___________ heat comes from deep inside the earth.

• Nuclear

• Hydro

• Geothermal

• Solar

A species of animals or plant that is _____no longer has any living members, either in the world or in a particular place.

• extinct 

• rare

• survival  

• productive

Coal power stations __________ sulphur dioxide into the atmosphere.

• clean 

• build   

• release  

• use

 

We should develop such ______ sources of energy as solar energy and nuclear energy.

• tradition

• alternative

• revolutionary

• surprising