Can Dogs See Colors?
Man's best friend is colorblind (色盲). Fortunately (fortunate), his （41）_____(survive) does not depend upon the ability to see colors. The （42）_____ (sharp) of his sense of smell makes up for his（43） _____ (fail) to see colors. It helps him to tell between things.
（44）_____ (study) support the conclusion that dogs live in a （45）_____ (color) world. The testing done primarily （46）_____ (focus) on the dogs' responses to colors for food. Dogs could not tell the （47）_____ (differ)between one color signal for food, and other colors that were not for food.
Most animals' lack of ability to see colors can be （48）_____ (easy) understood. Many colorblind animals hunt for food in the dark of night. Their other senses have highly （49）_____(develop). Thus their lack of color vision does not affect them.
Other animals with color vision are （50）_____ (monkey) and apes(猿). Both can be trained to open a colored door, behind which is food.
1. survival
2. sharpness
3. failure/failing
4. studies
5. colorless
6. focused
7. difference
8. easily
9. developed
10. monkeys
