a serious chronic ailment的用法和样例：
- Backgroud Acquired immune deficiency syndrome (AIDS) was caused by human immunodeficiency virus (HIV), and it is a serious chronic contagious disease and could not be cured.
背景与目的 艾滋病是获得性免疫缺陷综合征(acquired immune deficiency syndrome，AIDS)的简称，它是由于感染了人类免疫缺陷病毒(human immunodeficiency virus，HIV)后引起的一种无法治愈的致死性慢性传染病。
- The poor man has a serious disease of the liver.
- He received a serious wound in the battle.
- That put us at a serious disadvantage.