1. The mortality rate in the region has been steadily decreasing over the past few years.
在这个地区，死亡率在过去几年里稳步下降。

2. The study aims to examine the factors that contribute to mortality among elderly populations.
这项研究旨在研究导致老年人死亡的因素。

3. The mortality toll from the recent natural disaster has been devastating.
最近的自然灾害造成的死亡人数惨重。

4. Improvements in healthcare have led to a decline in infant mortality rates.
医疗保健的改善导致了婴儿死亡率的下降。

5. The high mortality rate among certain species is a cause for concern.
某些物种的高死亡率令人担忧。

6. The mortality of soldiers in battle is a tragic reality of war.
战争中士兵的死亡是一个悲剧性的现实。