中級閱讀模擬測驗　第十回

Have you ever wondered why the daytime sky looks blue? Sunlight may seem white, but it is actually 11 of many colors. As sunlight enters the air, tiny gas molecules scatter it in all directions. Blue light has shorter waves, so it is scattered much 12 than other colors. This is why blue seems to fill the whole sky. At sunset, however, the light must 13 through more air before reaching our eyes. Most of the blue is scattered away, so we 14 see warm reds and oranges instead. Understanding this simple science helps us 15 the beauty of nature every day.

Bees play a key role in nature, yet few people know how cleverly they find food. When a bee discovers a rich field of flowers, it flies back to the hive and performs a special “dance.” The direction and speed of this dance tell the other bees exactly 16 the flowers are. Scientists were amazed to 17 that this simple movement carries so much information. Bees also use the position of the sun as a 18 to find their way home. Sadly, the number of bees has been 19 in recent years because of chemicals and habitat loss. Protecting them is important, since our food supply greatly 20 on their work.