Airborne germs are ______ yet surprisingly few are virulent; despite the fact we inhale them with nearly every breath, the vast majorities of them are innocuous and are neutralized easily by our immune system.
【正确答案】
A
【答案解析】解析：由后半句的yet surprisingly可知，此处应填与few are virulent相反的意思，所以应为看起来到处可见的意思。ubiquitous“普遍存在的，似乎无处不在的，十分普遍的”：intolerable“不能忍受的，无法容忍的”；omnipresent“无所不在的，同时遍在的”；plentiful“丰富的，大量的”。只有A符合事实，故选A。