Choose the sentence which has the closest meaning to the original one.

No matter how small, every action to protect the environment is valuable.

Plastic takes hundreds of years to decompose in the ground, that is harmful to the environment.

Plastic takes hundreds of years to decompose in the ground, in which is harmful to the environment.

Plastic takes hundreds of years to decompose in the ground, which is harmful to the environment.

Plastic takes hundreds of years to decompose in the ground, from which is harmful to the environment.

I always turn off the fans when I leave the room and which that helps save energy.

I always turn off the fans when I leave the room, which it helps save energy.

I always turn off the fans when I leave the room, that helps save energy.

I always turn off the fans when I leave the room, which helps save energy.

People must never take their helmet off while they are riding a motorbike.

Those who are wearing a helmet are not allowed to ride a motorbike.

It is the helmet that one needn't wear when he is riding a motorbike.

You should not wear a helmet when you are riding a motorbike.

Recycling saves resources, but it causes more pollution.

Recycling not only saves resources but also helps reduce pollution.

Recycling causes both resource loss and pollution.

Recycling has nothing to do with pollution or resources.

Public transport increases traffic jams and air pollution.

Traffic congestion and pollution are reduced by using public transport.

The best way to pollute the air is by using public transport.

Using public transport does not affect pollution.

Peter promised to buy Mary a beautiful dress.

Peter said thanks to Mary for her beautiful dress.

Peter asked Mary how she had just bought her beautiful dress.

Peter complimented Mary on her beautiful dress.