单项选择题

The terrible pain during a crisis is caused by______.

A．the angular shape of the defective blood cells
B．the cutoff of oxygen supply in parts of the body
C．the cells stuck in the blood vessels
D．eating spoiled food

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热门试题

单项选择题

In the Middle Ages, the copying work of books was mainly done by______.

A．monks
B．intellectuals
C．artists
D．merchants

单项选择题

The author of the passage was______.

A．critical of the size of the space shuttle deck
B．amazed by the various exhibits in the Hong Kong Space Museum
C．a Jumbo jet lover
D．was fascinated by the sights of Hong Kong Island