Differences in case fatality between high and low pollution areas could be due to many factors other than co concentrations . 轻、重污染区致死病的方面的差别可能是一氧化碳浓度以外的许多因素所造成的。
2.
And australia ' s leading animal research facility is helping global efforts to control the deadly bird flu 澳洲开展的野生动物调查工作有助于进一步控制禽类致死病的扩散。