In such situations specific laboratory tests are necessary to establish the etiology.在此情况下,需要特异性实验来确定病原.Acute sinusitis is usually initiated by an acute respiratory tract infection of viral etiology.急性鼻窦炎常常是由病毒性病因的急性呼吸道感...
Our country population is numerous, per capita has farmland amount low, and mothball resource lack.我国人口众多, 人均占有耕地数量低, 且后备资源缺乏.Up to 1989, the growth of per capita income averaged 1 per cent per year.一直到1989年，人均收入每年平均增长1％...