An animal species becomes extinct when it fails to produce enough young in each generation to keep pace with the death-rate.
当一种动物不能在每一代都繁殖出足够的后代而与其死亡率保持一致时，它就会逐渐灭绝了。
By the turn of the century, Pittsburgh had the highest death rate in the United States.
到了世纪交替时，匹兹堡的死亡率居全美之首。
On the other hand, the death rate from flu dropped from 7.4 percent in 2000 to 4.1 percent in 2014.
另一方面，流感的死亡率从2000年的7.4%下降到2014年的4.1%。
So imperfect was this so-called cure that the death rate attributed to diabetes actually went up.
这种所谓的“治愈”方法是那么地不完美，以致糖尿病的死亡率反而上升了。
But the increased death rate was most stark in unmarried men over the age of 70 -and it has been increasing every decade.
但是这种死亡几率的递增在年龄超过70岁的未婚人群中更为明显。而且每过十年死亡率就会更大。
But more significant is the decline in the death rate, or deaths spread across miles of driving — long division that helps smooth out effects of economic cycles.
不过，死亡率的下降，也就是按英里数计算的死亡人数的下降更为重要，因为这种计算方法有助于消除经济周期的影响。
Of the 20 countries with the highest maternal mortality ratios worldwide, 19 are in Africa; and the Region has the highest neonatal death rate in the world.
全球范围具有最高产妇死亡率的20个国家中有19个在非洲；该区域新生儿的死亡率也居世界之首。
Among women who had breast cancer, those who took hormones also had a higher death rate from other causes - 0.05 percent per year, versus 0.03 percent per year.
那些患有乳腺癌，同时服用激素的妇女因其他疾病死亡的几率同样比对照组高，每年的死亡率分别是0.05%和0.03%。
The death rate after haemorrhagic strokes was 25.5% in American hospitals but only 19.8% in OECD countries as a group.
在美国，出血性中风后的死亡率为25.5%，而在全体经济合作与发展组织国家中，该比率仅为19.8%。
In New York City, the Bronx has the highest AIDS death rate of any borough, even though Manhattan has a higher rate of cases.
在纽约，尽管曼哈顿有着更高的感染率，但布朗克斯区的艾滋病死亡率是最高的。
The mortality figures were even closer, with a 68.7% death rate aboard the Titanic and 67.3% for the Lusitania.
两船死亡率更接近，泰坦尼克号上的死亡率为68.7%，而卢西塔尼亚为67.3%。
In later years, an increase in the death rate probably made a contribution to further declines in prevalence, while the number of new infections remained more or less unchanged.
在接下来的几年里，死亡率的升高更进一步降低了艾滋病的流行，但新增感染人数变化不大。
That could be because doctors are more nervous about the effects if flu on pregnant women and are more likely to admit them, but the death rate among pregnant women is high.
这是因为如果孕妇感染了猪流感，医院会出于对其后果的考虑而颇为紧张，于是更愿意接纳她们入院治疗，但是孕妇的死亡率仍居高不下。
She collected statistics which proved that the death rate for young soldiers in peace time was double that of the normal population.
她根据收集的统计数据证明在和平时期年轻士兵的死亡率是普通人的两倍。
Huang Yi, the deputy administrator of the work safety agency, said stricter scrutiny, regulations and the closing of 12, 000 mines had cut the death rate by three-fourths since 2002.
这个安全生产机构的副主任黄益(音译)说，由于严格的监管和制度，加上关闭了12 000个小煤窑，死亡率从2002年以来已经减少了四分之三。
Had he lived a little later, Horace might have found out from the U.S. Census Bureau that the death rate is usually lower in autumn than in winter and spring.
要是贺拉斯晚出生那么几年，他可以从美国人口普查局发现，秋天的人口死亡率一般低于冬、春两季。为什么呢？
This death rate may be as high as 25% among people who are displaced, malnourished and have poor access to health care.
这一死亡率在流离失所、营养不良和难以获得卫生保健的人群中可能高达25%。
I was gratified that the death rate from AIDS was coming down, and I was determined to keep pushing for more research to develop lifesaving medicines.
让我满意的是，艾滋病的死亡率已经下降，我决心继续推动更多的研究来开发救命的药品。
There was no significant difference in the number of women developing lung cancer, but those on anti-oestrogens did have a lower death rate.
女性患有肺癌的数量没有差别，但是服用抗雌激素药物的死亡率更低一些。
Although Britain's adolescent death rate is low compared with that of most countries, its morbidity rates - the long-term damage done not only by alcohol but also by obesity - are high.
与其它大多数国家相比，虽然英国青少年死亡率低，但是它的致命率(酗酒和肥胖造成的长期伤害)是高的。
The last time it was so low was in 1950, when the death rate was much higher.
上一次这么低的增率是在1950年，当时死亡率比现在高多了。
The sixth leading cause of death was Alzheimer's disease, one of six diseases or causes for which the age-adjusted death rate increased significantly, the study says.
第六号死亡因素是老年痴呆症，据研究称，这是导致年龄调整死亡率上升的重要的六种疾病中的一种。
And you can reduce also the side effects, which is very important because we know that the death rate is mainly higher when people are not put early on treatment.
治疗中的副作用也可以减轻。这很重要，因为我们知道死亡率高主要是由于感染者没有得到初期治疗。
Russia's population is shrinking alarmingly, its death rate double that in most developed countries.
俄罗斯的人口正以令人担忧的速度减少，其死亡率是大多数发达国家的两倍。
The death rate in patients who experience only this form of the disease is low, although residual neurological deficit, which may be severe, is common.
仅患此种病症的患者，其剩余的神经功能缺损很常见，病情可能会很严重，但死亡率不高。
If they did, they could pass the virus to their infants, and they had a higher infant death rate than that of uninfected females.
即使雌性黑猩猩能够生育，她们也会将病毒传染给她们的婴儿，并且其婴儿死亡率比没有感染的雌性所生育的婴儿的死亡率要高。
For persons able to develop an immune response the death rate is usually within the range of 10-15%.
对能够形成免疫反应者，死亡率通常在10- 15%的范围之内。
For persons able to develop an immune response the death rate is usually within the range of 10-15%.
对能够形成免疫反应者，死亡率通常在10- 15%的范围之内。
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