英语语法分析

The American Lung Association (ALA) has issued new guidelines on combating colds and the flu, and one of the keys is being able to quickly tell the two apart.

美国肺脏协会（ALA）已经发布了对抗感冒和流感的新指南，其重要意义之一是能够快速地将两者区分开来。

The ALA notes that it may be particularly difficult to tell when infants and preschool age children have the flu.

美国肺脏协会指出，判断婴儿和学龄前儿童何时会患流感可能尤其困难。

Results suggest that topical ALA-PDT is a simple and effective treatment for urethral condylomata acuminata.

ALA-PDT 是治疗尿道尖锐湿疣的一种简单、有效的新疗法。