单项选择题
A．A love letter B．A complaint letter C．A thanks letter D．An invitation letter
A．A doctor's notebook. B．A diary. C．A magazine. D．A school biology book.
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