四、阅读短文,从方框中选出能填入文中空白处的最佳选项,选项中有两项为多余选项
You may answer white or blue. Surprisingly, there are green icebergs (冰山) in Antarctica.
Many icebergs look white because they are covered with white snow. Some young icebergs look white because there are a lot of small bubbles in the ice. All these lights mix together and turn white in people's eyes. When the ice in icebergs becomes compact (坚实的) over the years, it can only reflect lights like blue.
Scientists studied their unusual colour for years. But now we know the answer—the iron oxide (铁氧化物) from rock dust (岩粉). The glacial ice with iron oxide in it drops from the Antarctic ice sheets (冰盖), mixes with ocean water and then freezes to be green icebergs.
Apart from white, blue and green, there are also icebergs in yellow, black and other colours. From them, we can know more about the planet.
A. What colour are icebergs?
B. Who found the icebergs in Antarctica?
C. But why do some icebergs look green?
D. That's why many icebergs appear to be blue.
E. The bubbles reflect lights in different colours.
F. So we should stay away from icebergs when shipping.
G. Many mysteries about them are waiting for us to solve.
36. ______ 37. ______ 38. ______ 39. ______ 40. ______