Scientists think that most animals can't see colors. The world is black and white to them.
    To find out if dogs could see colors, scientists gave dogs food every time they played a certain piece of
music. The dog got ready to eat only when they heard this piece of music. They did not get ready to eat
when they heard other piece of music.
    Then the scientists gave the dogs food every time they showed them a certain color. The dogs got ready
to eat when they saw this color. The scientists then showed the dogs another color. Again the dogs got ready
to eat. The colors were all the same to them.
    Colors are not all the same to the monkeys, however. For example, if we put food in a red box and do this
every day, a monkey will always go to the red box to get the food. If we then put food in a blue box, the
monkey won't go to it.

1. All colors are the same to           .

A. all animals
B. scientists
C. monkeys
D. dogs

2. Monkeys know that red and blue are           .

A. not the same
B. the same
C. colors
D. food

3. The scientists give the dogs food every time they           .

A. saw the color red
B. went to a box of food
C. saw the color blue
D. played certain music

4. Dogs are different from monkeys because           .

A. dogs can't see any colors and monkeys can
B. dogs can't see more colors than monkeys
C. monkeys can't see any colors and dogs can
D. monkeys can't see red and blue

5. Some            wanted to find out if dogs could see colors.

A. animals
B. doctors
C. scientists
D. monkeys