题目内容：

阅读理解(2014贵阳)

  Paul Nicklen waited patiently on a sheet of ice in the Arctic．He was there to take pictures for National Geographic．Finally，he saw something big and white．It was a polar bear，swimming towards him in the icy water．

  Paul lay down on the ice to get a better photo，but the polar bear jumped out of the water and tried to attack him！Luckily for Paul，the ice cracked，or broke．and the bear fell back into the water．The polar bear wasn’t so lucky．It couldn’t get a meal and had to swim farther away to find food．

  To understand the polar bear’s problem，you need to know two things about the Arctic．First，the Arctic is mostly ocean．Second，ice covers a lot of the Arctic Ocean．In winter，the ice forms a thick，white sheet，but in summer，the ice becomes thinner and breaks into pieces．Sea ice is the key to survival(幸存)for Arctic animals．However，because of global warming，Arctic temperatures are rising and polar ice is melting．

  Polar bears need ice to hunt seals，their favorite meal．They stand on the ice and wait for the seals to come up for air．As Arctic ice melts，polar bears have to swim farther to find ice floes，or large pieces of floating ice．Sometimes，bears have to swim more than 200 km to find an ice floe．Some bears cannot swim that far and，sadly，they drown．

  On his last trip，Paul Nicklen saw three dead bodies of polar bears．Before global warming threatened Arctic ice，a dead bear was a rare sight．Paul is sad to see the dead bodies．Wildlife experts think global warming will have a terrible effect on polar bears．In the future，polar ice will continue to shrink and endanger the bears．some scientists believe 65 percent of the world’s polar bears will disappear by 2050．In other words，polar bears are in great danger．

1.The main idea of the passage is that________．

A．polar bears are amazing swimmers

B．Arctic temperatures are rising

C．global warming is endangering polar bears

2.The polar bear that tried to attack Paul was unlucky because________．

A．Paul swam away

B．it was on an ice floe

C．it couldn’t eat Paul

3.According to the passage，polar bears hunt seals by________．

A．waiting on the ice

B．waiting in the water

C．drowning the seals

4.From the passage，Paul Nicklen is maybe a________．

A．scientist

B．photographer

C．psychologist

5.We can infer that polar bears________．

A．won’t have any food in 2050

B．will all die before 2050

C．cannot find food easily