Complete the text with the correct word. fill in : save , energy , throw away , power , containers, landfill , breaks down. a(n) is a deep hole in the ground. when we our rubbish,this is often where it ends up. as this waste , it produces a mixture of gases known as landfill gas. scientist are trying to find ways to use it as a(n) 4) source , but it is still too dangerous and harmful to us and to the earth. maybe one day we will be able to use this gas to 5) our cars , but not yet. we should recycle all glass , plastic and metal in the correct bins. if we do this , we will .