题目内容：
根据下面资料，回答题 Many animals have an excellent sense of smell, which they use in hunting. On the other hand, their eyesight may be poor. Dogs, for example, have pooreyesight and no color vision. They see only shades of gray. But a dog's sense of smell is extraordinary.
The kind of dog known as Alastian has 220 million olfactory cells. Man has five million. Scientists believe that the Alastian is one million times better than man in finding out odors.
The human sense of smell, however, is really quite good. The average human being can distinguish more than 10000 different odors.
According to the passage, which of the following facts is not true? A．Many animals have poor eyesight while their sense of smell is quite good.
B．Dogs are color blind.
C．The human sense of smell is not good.
D．Dogs can see no more than shades of gray.
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