For years we have believed we were either healthy or sick. (55) , during the mid-90s, scientists developed a new concept called "sub-health", a status (56) health and illness. The concept of sub-health has become (57) because it has helped to explain many health problems. (58) one study, only 5. 6% of people in the overall population are actually sick, (59) the subhealthy group consists of about 60%, and the (60) population is considered healthy. (61) of one’s sub-health will help one to be alert to the underlying disease and remain healthy. Sub-health is a state in which the body is (62) turning from health to illness or from illness to health. Our bodies are actively (63) the conditions of health, sub-health and disease. Factors (64) aging, internal or external toxicity (毒性), and body or mind exhaustion may cause sub-health, but taking good care of the body can change a sub-healthy status to a healthy one.
63().
A.since
B.though
C.for
D.whereas
参考答案：D
解析：
本题测试上文文逻辑关系。文中说5.6%的人是不健康的，而百分之60%的人口却处于亚健康状态。since意为“自从；因为”；though“虽然”；for意为“因为”；whereas“而，却”。只有whereas表示转折，所以D选项是正确答案。