Go back to the text and find the words and phrases

Go back to the text and find the words and phrases in bold to replace the underlined phrases in the sentences below. 1 A lot of ecological catastrophes occur because people do not observe official rules for preventing danger. 2 Factories and plants lei a lot of waste qq into the air and water. 3 In summer a lot of young people join groups of people who offer their help without payment, taking care of animals in wildlife reserves. 4 It is not worth spending money to work hard on the effects of the pollution problem. Its much better to deal with its cause.