In the following passage, some words have been deleted. Select the most appropriate option to fill in each blank.

Pollution is destroying nature. The smoke that is (1) ______ from the chimneys of the factories, and from vehicles is the mixture of poisonous gases. Due to environmental pollution, there is (2) ______ in nature, so, many birds, animals, and plants are on the verge of (3) ______ day by day. The only way to (4) ______ environmental pollution is to plant many trees. By planting trees, we can get rid of many harmful poisonous gases. It is the responsibility of everyone to (5) ______ and protect our environment.

Select the most appropriate option to fill in blank number 1.