1. The rise of acquired immune deficiency syndrome (AIDS) around the earth has represented a major challenge to medical progress both in developed and in less — developed countries.
    全球艾滋病的蔓延无论在发达国家还是在欠发达国家都是对医学进步的重大挑战。

2. There are three stages of iron deficiency.
    缺铁分为三个阶段：

3. However, most people with low iron reserves don't know they have a deficiency, because traditional methods of calculating the amount of iron in blood (by checking levels of the blood protein that transports oxygen) are not sufficient, Beard states.
    然而，比尔德指出，大多数铁离子储量低的人并未意识到自己缺铁，因为传统的检测血液中铁离子储量的方法——只检验血液中输送氧气的血蛋白的含量——是不够的。

4. Acquired Immune Deficiency Syndrome (AIDS) was diagnosed in the United States in the late 1970s.
    艾滋病是20世纪70年代末在美国被发现的。

5. And because women often restrict their diet in an effort to control weight, they may not consume enough iron-rich food, and are liable to experience a deficiency.
    而且，由于女性常常为了控制体重而节食，而未能摄取足够的含铁丰富的食物，结果可能导致缺铁。

6. "For a woman who already has a poor iron status, any additional iron loss from exercise may be enough to tip her over the edge into a more serious deficiency," notes the expert.
    他提醒说，"对于那些已经缺铁的女性，任何因锻炼而产生的更多铁离子流失都足以导致体内缺铁状况的恶化。"

7. "If you pay attention to warning signs before iron reserves are gone, you can remedy the deficiency before it really becomes a problem."
    "如果你在铁离子储量流失之前就注意到了警告信号，你就可以在它真正成为问题之前弥补铁离子的不足。"

8. Iron deficiency is very common among women in general, affecting one in four female teenagers and one in five women aged 18 to 45, respectively.
    缺铁在多数女性中是很常见的，十多岁的少女四人中有一人缺铁，18至45岁的女性五人中有一人缺铁。

9. If iron levels are low, talk with a physician to see if the deficiency should be corrected by modifying your diet or by taking supplements.
    如果铁离子含量低，就要去看医生，以确定是否该通过调整饮食或服用铁离子补剂来校正不足。

10. Fatigue and poor performance may begin to appear in the second stage of deficiency, when not enough iron is present to form the molecules of blood protein that transport oxygen to the working muscles.
    到了缺铁的第二阶段，就会出现疲倦和力不从心，此时体内已没有足够的铁来形成血蛋白分子，将氧输至运动着的肌肉。