Comprehension of passages for practice for class 10th

Alaskan polar bears have mastered the art of living in ice. Even during the frigid days of winter, these furry white creatures don’t hibernate in cozy dens, like other bears do. Instead, they go north, hunting for seals living in the ice-covered water.

In recent years, however, Earth’s climate has been getting warmer, and ice near the Poles has been melting. Now, a new study shows that disappearing ice is changing polar bear behavior. For instance, more than half of pregnant polar bears used to give birth in dens on solid blocks of ice that were floating out at sea. Today, they’re digging their dens on or near land.

The reason? Most of the ice has disappeared. Studies have shown that 27 percent of sea ice in the Arctic that stays frozen from year to year has disappeared during the past 30 years. So there’s now much less space for dens. Moreover, as the warming continues, the remaining ice becomes less stable. These conditions are unappealing to mother polar bears, who want a safe place to give birth. A mother polar bear often has two cubs at a time. Baby cubs stay with their mothers for more than 2 years.For now, Alaska’s polar bears seem to prefer returning to land rather than taking the risk of giving birth on shaky ice. That solution might not work forever, however, especially if the ice keeps melting. The bottom line? Polar bears are in trouble.

Answer the following questions.

1. Where do seals live?
2. Describe one trait that makes Alaskan polar bears different from other bears.
3. Polar ice is melting. Why?
4. What has forced polar bears to dig their dens on or near the land?Answers

1. Seals live in the ice-covered water of the north.
2. Alaskan polar bears are different from other bears in that they do not hibernate during winter. Instead, they go north hunting for seals.
3. Ice near the poles is melting because the earth’s climate is getting warmer.
4. Polar bears are now digging their dens on or near the land because the ice that used to float out at sea has disappeared.

from 

http://perfectyourenglish.com/blog/class-10-reading-comprehension-exercise/