The,American Lung Associations(ALA)has issued new guidelines on

The,American Lung Associations(ALA)has issued new guidelines on combating colds and the flu,and one of keys is being able to quickly tell the two apart.That's because the prescription drugs available for the flu need to be taken soon after the illness sets in.
【正确答案】：这是因为治疗流感的处方药必须在流感发病初期立即服用。【解析】原句是主系表结构的复合句，because 引导原因状语从句作表语，available for the flu是prescription drugs的后置定语，汉译时译作前置定语“治疗流感的”，soon after 引导时间状语从句，汉译时将soon after后置。