Join the sentences in two ways, with or without which/that. a) a lot of rubbish is floating in the sea. it is a real danger to health. b) the problem of soil erosion is discussed in this chapter. it has occurred ever since the man began destroy forests. c) nuclear energy comes from the energy stored within the nuclei of atoms. they are the basic building blocks of all matter. d) the best things in life such as water and air are free. we often take it for granted. e) the manufacture of one pc requires 28kg of liquid chemicals. all liquid chemicals have to be neutralized by a further 11 kg of sodium hydroxide.

A) A lot of rubbish that is a real danger to health is floating in the sea.
A lot of rubbish is floating in the sea and it is a real danger to health.
b) The problem of soil erosion which has occured ever since the man began to destroy forests is discussed in this chapter.
The problem of soil erosion has occured ever since the man began to destroy forests and is discussed in this chapter.
c) Nuclear energy comes from the energy stored within the nuclei of atoms which are the basic building blocks of all matter.
Nuclear energy comes from the energy stored within the nuclei of atoms and they are the basic building blocks of all matter.
d) The best things in life such as water and air which we often take it for granted are free.
The best things in life such as water and air are free and we often take it for granted.
e) The manufacture of one PC requires 28kg of liquid chemicals which have to be neutralized by a further 11 kg of sodium hydroxide.