单项选择题
A．made B．built C．did D．started
A．People are more likely to catch cold in the winter. B．Colds are so common that even the strongest person cannot avoid it. C．Old people are likely to catch cold because they are unpleasant. D．Colds can never be cured without the help of medicin
A．They made laws that protect birds. B．They taught young people, helped pass laws that protect animals and so on. C．They tried to make the world better. D．Both B and C.