单项选择题A．American doctors would pay the medical bills. B．American doctors are paid by the government. C．The patients should pay for the doctors’ service. D．The government would pay for the medical bills.

单项选择题A．It cannot contain any commercial information. B．It may not be of a high level of security. C．One can only use the free e-mail account at home. D．It is difficult to get access to the website with such service.