单项选择题
A．Colds are always very dangerous. B．Colds are often unpleasant though not dangerous. C．Actually nothing can help get rid of colds. D．The best way to keep colds away is to be healthy.
A．held B．took C．set D．planed
A．The United States. B．Some persons loving birds. C．People who think of the birds. D．Audubon’s future generation.