Analyze the sentences according to structure and grammar us

Analyze the sentences according to structure and grammar use.
1. The (‘s) in “The Amazon is often called the lungs of the earth and produces 20% of the world’s oxygen.”, is the contraction for the verb to be (is).
2. In “In order to work in the park, conservationists need a reliable map. However, no map existed, and they didn’t have enough knowledge to make one on their own.”, the underlined pronouns refer to ‘conservationists’
3. The phrasal verb ‘cut down’, in the second paragraph, means to reduce the amount.
4. The negative form of “They came up with the idea of involving local tribes to help them, combining modern and ancient methods to produce a map.” is They didn’t come up with the idea of involving local tribes to help them, combining modern and ancient methods to not produce a map.
Choose the alternative which presents the correct sentences.