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EXERCISE 3 Improving Unity and Adding Details
Work with a partner or small group to revise the following paragraph. Cross out any
words or sentences that weaken the paragraph's unity because they move away from
the main idea. Then from the list at the top of page 25, select the details that you think
would improve the paragraph. (Some of the details can be inserted as phrases and
clauses.) Write the letter of the detail where you think it belongs in the paragraph. Then
write your revised paragraph on a separate piece of paper.



'Several theories have been advanced to explain the disappearance of dinosaurs from
Earth. The current favorite theory is that a gigantic asteroid struck Earth approximately
65 million years ago. The impact created billions of tons of smoke, dust, and debris in
Earth's atmosphere. 'Plants died, then plant-eating dinosaurs, then the dinosaurs that fed
on the plant-eating dinosaurs. 'By examining the anatomy of dinosaur fossils, scientists
can decide whether dinosaurs ate plants or animals or both. Tyrannosaurus rex, a
a widely studied dinosaur, was a flesh-eating dinosaur. There are other theories, too.
"Some speculate that dinosaurs became extinct because of climate changes. "Other
scientists think they may have been wiped out by a dinosaur disease; still others believe
that mammals might have wiped out all dinosaurs by eating their eggs.