Editorial Development: Bonnie Brook Communications

SKILL PRACTICE
Read each question. Fill in the bubble next to the correct answer.
 1. People most likely make the trip to the Cave of 
Crystals because 
.
A 
gypsum is a rare and valuable mineral
B 
they want to see how long they can survive in 
the cave 
C 
they enjoy dangerous situations
D 
it is a beautiful and fascinating place
 2. You can infer that cave visitors wear special vests 
in order to 
.
A 
identify them as important people
B 
protect them from the heat in the cave
C 
make them more visible to one another
D 
enable them to carry equipment 
 3. From what you read in the passage, why must cave 
explorers wear breathing masks?
A 
There is no oxygen in the cave. 
B 
The air in the cave is too hot to breathe.
C 
There are poisonous gases in the cave.
D 
There is a bad smell in the cave. 
 4. If someone stayed in the cave longer than 20 
minutes, the person would probably 
.
A 
become dangerously sick
B 
be fined for staying too long
C 
get tired of looking at the crystals
D 
gradually get used to the conditions 
STRATEGY PRACTICE
Compare the organization of the second paragraph to that of the third paragraph.
 
Make Inferences
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10/31/12 7:34 AM

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© Evan-Moor Corp. • EMC 3458 • Daily Reading Comprehension 
63
Name: 
WEEK 9
DAY 5
READ THE PASSAGE
Use details from the passage to make inferences and comparisons.
The Intelligence of Dolphins
Dolphins are widely thought to be playful, social creatures, but are they intelligent? The notion of 
dolphin intelligence has been around for decades, and over time, many documented observations of 
dolphin behavior have suggested that they are extremely smart.
There are over 30 species of dolphins, and each type is unique. Although the various species have 
their differences, all dolphins use the same systematic methods to obtain food and to survive. These 
marine mammals can flawlessly synchronize their movements with one another. They hunt prey in groups, 
surrounding schools of fish, for example. Dolphins communicate with each other through whistles and 
other sounds, and they also use echos of sound to navigate and hunt, a process known as echolocation.
Even though they live in water, dolphins are classified as mammals. Unlike fish, they need to breathe 
air to survive. Dolphins rise to the ocean’s surface to gather air through blowholes and are frequently 
spotted skipping through the water or gliding along next to boats. While this behavior has greatly 
contributed to the assumption that dolphins are playful and friendly, scientists believe that dolphins swim 
next to boats in order to ride on the currents created by the vessels. Known as “bow riding,” this style of 
swimming conserves the dolphins’ energy.
Dolphins have been known to do some amazing things, such as swim blindfolded, fend off sharks, 
and imitate humans. In Hawaii, a dolphin imitated a human diver who was cleaning algae off an 
underwater glass window. The dolphin, named Daan, started scraping the glass clean with a seagull 
feather! As dolphins continue to grow in popularity, more opportunities are sure to become available to 
those who want to observe these fascinating creatures.