假设你是刘梅，请你就本市某些开发商无计划拆除旧建筑，改造城区的现象给市长写一封信，内容应涉及进行城区改造的必要性、没有计划地拆除旧建筑的危害，以及你本人的观点和建议。

A．the increasing number of patients
B．the widespread medical knowledge on the Internet
C．the patients' regular visits to doctors that occupy too much time
D．new diseases and symptoms emerge constantly

A．Hypochondria happens to everybody sooner or later.
B．We needn't worry about hypochondria since it is not dangerous at all.
C．Hypochondria originates from too much knowledge of medicine.
D．Not only individuals but also the healthcare system might be disturbed by unnecessary terrors.