单项选择题A．The relationship between man and his environment.B．The relationship between living things and their environment.C．The relationship between man and living things.D．The relationship between man’’s brain and other living things.

单项选择题According to the passage, there are more myths about the common cold than any other human disease because________.

单项选择题The hydra is a kind of ________.

单项选择题Eating too much salt can raise your cholesterol.

单项选择题A．Both Sarah and Tom have been awarded doctoral degrees.B．Tom has arranged to meet his bride Sarah in Hawaii.C．Tom was more excited than Sarah at the wedding.D．A double blessing has descended upon Tom.