读图，分析回答我国一些地区出现的生态环境问题的原因及其治理措施。（15分）

(1）①地区草地退化严重，其自然原因是＿＿＿＿＿＿＿＿＿＿＿＿，该地区淹没在沙漠中的古代文明遗址有＿＿＿＿＿＿＿＿＿＿＿＿。（2分）

(2）①—②地区土壤侵蚀和草地退化比较严重的人为原因是＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿。（3分）

(3）③④⑤三个地区生态环境问题的共同特点是＿＿＿＿＿＿＿＿＿，原因是＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿。（4分）

(4）④⑤地区也是我国酸雨影响严重的地区，酸雨对土壤的危害是＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿，请你为该地区酸雨的防治提出合理化的建议。（6分）

In the workplace, influenza is typically spread by infected individuals to others with whom they work in close quarters. A new medication that suppresses the symptoms of influenza therefore will actually increase the number of influenza cases, because this medication will allow people who would otherwise be home in bed to return to work while infected.
Which of the following, if true, most seriously challenges the prediction

A．Coughing, a symptom of influenza that the new medication suppresses, is a primary mechanism in the spread of this illness.

B．Some medications that are used to suppress symptoms of influenza are also used by many people to treat symptoms that are caused not by influenza but by other illnesses.

C．Many workers who now remain at home when infected with influenza do so because the symptoms of influenza prevent them from performing their jobs effectively.

D．Most adults who are immunized against influenza in order to avoid being infected are over 65 years old and retired and thus do not work outside the home.

E．(E) Symptoms of an illness are often the body’s means of curing itself of the illness, and therefore suppression of symptoms can prolong the illness that causes them.