How to write a outline?

How to write a outline?
How to write a outline?

How to write a outline?
写好提纲的要点是简明、有层次、概括好大意.主要由introduction,main idea, conclusion组成.注意层次标号要分清楚.下面我附上了我在美留学期间写的一篇提纲,你可以参考一下这个模式,希望可以帮到你.
Outline of Plastic Trash in the Ocean
Introduction:
In my hometown factories dump a variety of plastic trash, sewage and toxic chemicals into the local reivers. The situation is terrible, but nobody cares about it. Most people believe that rivers finally reach the ocean. No matter how much trash we dump into the ocean, it is too big to be polluted. But Plastic trash is a heavy burden for Oceans. Marine life suffers a great deal from the plastic trash.
Main Idea 1-Plastic waste is a great danger to marine animals and seabirds.The use of plastic has increased dramatically since the 1940s.
A.Every single year, not only 77 tons of plastic are dumped into ocean by naval and merchant ships legally, but also 2,600 tons of plastic packaging material are abandoned into the sea by fishing industry.
B.Every year more than 200 different kinds of marine life are affeted by plastic to varying degrees.
Main Idea 2-Damage from fishing products also is a major threat to oceans wildlife.
A.149, 000 tons of fishing gear and marine debris are abandoned into the sea by fishing industry annually.
(1) Fishing gear continues to catch living animals at random.
(2)The top three killers are rope, fishing nets, and fishing line
B. Fishing gear drags along the sea bottom, which leads to destruction. The natural marine habitats are damaged by human beings.
Main Idea3-The trash is far away from habitats of humans, but the truth of plastic pollution is tough.
A.Hawaii is a convincing instance.
(1) Trash from all over the world, drifts into the Northern Hawaiian Islands
B. Light plastic waste is carried by the ocean currents, so it can appear on most remote beaches of the world.
(1)Researchers have reported the finding of plastic bags from the north Arctic Circle to the Falkland Islands.
Conclusion:
Earth is our home, and it is also the home for diverise animals. We can save them by doing something very simple in our everyday life. We can leave a clean, beautiful habitat for our children. Recycle plastic bags. Use paper bags instead of them. After fishing, bring all nets and lines to home. Do not leave anything behind for animals to become entangled. Be a kind person.Save our oceans. Save our planet. Save ourselves. You will feel happy.