S e c o n d e d I t I o n 1 Reading for the Real World 1

verge
of extinction. It also claimed that almost 40 percent of all species are 
“threatened” with extinction, including 33 percent of all 
amphibians
, a quarter of 
the Earth’s 
coniferous
trees, and about 12 percent of all birds. Of all threatened 
species on the red list, about 3,000 are “critically endangered,” which means 
they could disappear soon.
What would happen to people if the “Sixth Extinction” takes place? Scientists 
say life on Earth would be grim. There would not be enough food to eat, and water 
would be too polluted to drink. New species of pests and plants would invade the 
natural areas that remain. These invaders could carry new kinds of germs, causing 
diseases that human bodies cannot resist. Without plants to help cool the sun, the 
ice at the North and South Poles could melt, causing sea levels to rise and wash 
away coastal cities. By wiping out other species, human beings might be paving 
the way for the greatest extinction of all: their own.
Reading Time
_______ minutes _______ seconds
547 words
30
tropical --- relating to warm climates
36
status --- state or condition
38
verge --- brink or threshold
39
amphibian --- an animal with characteristics of fish and reptiles
40
coniferous --- cone-bearing

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R 
eading Comprehension
56
A
Mark each statement as either true (T) or false (F) according to the 
reading.
 1.
____ Some scientists estimate that half of all species will be extinct in the 
next century.
 2.
____ The Earth is facing its third mass extinction in history.
 3.
____ A higher percentage of bird species face extinction than coniferous trees.