阅读理解。
Polar bears (北极熊) are very big white bears. They live in the Arctic Circle (北极圈) near the North Pole
but they do not live at the South Pole. Polar bears live in the snow and ice. At the North Pole, there is only
snow, ice and water. There is no land. Sometimes you're hard (难的) to see the polar bears because their
coats are yellow-white. They have very warm coats because it is cold there.
An adult (成年的) bear can be three meters long and weigh (重) 450 kg. It can stand up on its back legs
because it has very large and wide feet. It can use its front legs like arm. The polar bear can swim very well.
It can swim 120 km out into the water. It has fish and sea animals for food.
1. What is a polar bear like?
A. It's like a white bear.
B. It likes fish.
C. It likes cold weather.
2. Where do polar bears live?
A. They live in the circle.
B. They live at the South Pole.
C. They live in snow and ice.
3. What's at the North Pole?
A. Snow and land.
B. Snow ice and water.
C. Ice and land.
4. What can a pole bear do?
A. It can swim.
B. It can make snow-man.
C. It can work.
5. What do polar bears eat?
A. They eat fruit.
B. They eat vegetables.
C. They eat fish.
。用1根短线不是1对电子的式子是结构式，所以氮气的结构式为
。因此只有选项A是正确的，答案选A。
