Question

air pollution essay
persuasive essay outline
introduction
thesis statement:
air pollution is a pollution for man. it can cause lung cancer, heart disease,
and asthma after exposure for long periods of time.
body paragraph 1
topic sentence
firstly, air pollution can cause lung cancer after exposure for long periods
of time.
body paragraph 2
topic sentence
secondly, air pollution can cause heart disease after exposure for long
periods of time.
body paragraph 3
topic sentence
conclusion
which should be used for the topic sentence of body
paragraph 3?
water is made of hydrogen and oxygen atoms.
in space, oxygen must be provided to astronauts in order for them to survive.
thirdly, air pollution can cause asthma after exposure for long periods of time.

Explanation:

The essay is about air pollution, and Body Paragraph 3's topic sentence should relate to the effects of air pollution. The first option is about water's composition, the second about oxygen in space, and the third about air pollution causing asthma. Since the essay's body paragraphs follow a sequence (Firstly, Secondly, Thirdly) about air pollution effects, the third option fits as it continues the pattern and is relevant to air pollution.

Answer:

Thirdly, air pollution can cause asthma after exposure for long periods of time.