单项选择题

Professor Laura believes that his research _________.

A．has been supported by many scientists
B．has a profound significance
C．has established a new theory on Vitamin Ｄ
D．has changed people's concept of skin cancer

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热门试题

单项选择题

It can be inferred from the passage that traditional skin cancer theory says _________.

A．natural sunlight may help prevent skin cancer
B．artificial light is too weak to cause skin cancer
C．exposure to the sunlight may cause skin cancer
D．Vitamin D is very important in preventing skin cancer

单项选择题

According to Professor Laura, it would be safer from skin cancer ifyou _________.

A．wore sunglasses when you were out
B．stayed indoors most of the year
C．used sunscreen creams when you were in the sun
D．let yourself be exposed to the sun when the sunlight is not too strong