I certainly hope that David is aware ______ all the problems imvolved.
A.in
B.of
C.at
D.on

A nuclear reactor releases ______ which is dangerous to the environment.
A.heat
B.carbon dioxide
C.energy
D.radiation

Solar energy can be changed ______ electricity.
A.for
B.in
C.into
D.to

We could make better ______ of our energy resources.
A.limit
B.need
C.use
D.spend

All fossil fuels are ______ resources that cannot be replaced after use.
A.unlimited
B.renewable
C.non-renewable
D.available

Choose the word which is stressed differently from the rest.
A.dangerous
B.ecologist
C.scientist
D.fertilizer

We are doing our best with the _______ resources available.
A.limit
B.limiting
C.limitation
D.limited

Gas and oil _______ always increases in cold weather.
A.consumption
B.consumer
C.consuming
D.consume

_______ damage threatens the whole of civilization.
A.Environmentally
B.Environmental
C.Environment
D.Environtalist

How to make full use of these sources of energy is a question for ______ all around the world.
A.consumers
B.customer
C.biologists
D.reseachers