All Eskimos live most of their lives close to salt or fresh water. They may follow game inland for several hundred miles, but they always return to the shores of rivers lakes, or seas. Eskimo land has a bare look. Large rocks, pebbles, and sand cover much of the surface. Plants called lichen (地衣) grow right on rock. And where there is enough soil, even grass, flowers, and small bushes manage to live. No trees can grow on Eskimo land, so geographers sometimes call this country the Arctic plains. Some animals, such as rabbits and caribou(北美驯鹿), eat the plants. Others, like the white fox and grey wolf, eat the rabbits and caribou. The Eskimo is a meat-eater, too, and may even eat a wolf when food is scarce. The Eskimo year has two main parts: a long, cold winter and a short, cool summer. Spring and fall are almost too short to be noticed. Summer is the good time, when food is usually plentiful. But it is also the time when the Eskimos are very busy. Winter is never far away, and the men must bring home extra meat for the women to prepare and store. For seldom can enough animals be killed in winter to feed a family. The Far North is sometimes called the land of the midnight sun. This is true in the middle of summer, for between April 21st and August 21stthe sun never sets in Northern Greenland. But in midwinter the Far North is a land with no sun shining at all. Around Oct. 21stthe Eskimos of Northern Greenland see the sun setting straight south of them, and they don't see it again until February 22nd. All places on earth get about the same amount of daylight during a year. As a result, if summer is lighter, winter has to be darker. Winter nights in the Far North are seldom pitch-blank. As in the rest of the world, the stars and moon provide a little light, The northern lights also help the Eskimo to see. And with the ground covered with snow, even a little light is reflected back to the Eskimo's eyes. Which of the following statements is NOT true?