Snakes help control the population of mice.

Statistics suggest that the population of this country will be double in ten years' time.

统计显示，这个国家人口在10年内将增加一倍。

But before they can be assured, more efforts must be made, because the population of the crane in the wild is on the decline, and many other species appear headed toward extinction.

它们得到保护之前需要我们做更多努力，因为野生鹤的数量正在下降，许多其他物种也似乎正在走向灭绝。

Caused by aging of the population of urban old-age pension is increasingly drawn wide attention and has become an important issue to many countries.

人口老龄化所引发的城市养老问题日益受到普遍关注，并已成为许多国家面临的重要课题。

The Population of Yanbian Has Entered a Modern Population Stage

试论延边人口已进入现代人口时期

Analysis of resistance to scab in the population of wheat gene pool group dates

抗赤霉病小麦基因库群体的抗性分析

Effects of Pesticide-contamination on the Population of Methanogens and Methane Emission in Paddy Rice Soil

农药污染对黄松稻田土壤产甲烷菌数量和甲烷排放通量影响的研究

"I learned that the population of Nepal is...."

"我了解到尼泊尔的人口是……"

Not a single day has been wasted, though I can never tell when knowing the population of Nepal might prove useful.

没有浪费一天时间,尽管我永远无法判断知道尼泊尔的人口这一点会在什么时候派上用场。

Stability Analysis of a Kind of Harvest Model for the Population of a Single Race

一种单种群收获模型的稳定性分析

A study on the population of yellow& breasted bunting at Changbai Shan

长白山黄胸鹀种群生态的初步研究

Vicissitudes of the Population of China Tartar Nationality and the Present Situation of Population Distribution

中国塔塔尔族人口规模的变迁和人口分布现状

The population of hydroxyl rotation level and it's influence to LIF

激光诱导荧光法测量OH自由基中激光产生的OH自由基转动能级布居及其对测量的影响

With the population of Digital TV, high definition television receiver will have excellent prospect in the future.

随着数字电视在我国的普及，高清电视接收机将会有广阔的市场前景。

Humans Dental caries in the population of the Neolithic Age

新石器时代人牙齿的龋病状况分析

Harvest Model and Its Stability Analysis for the Population of a Single Race with Age Group

基于年龄分组的单种群收获模型及稳定性分析

The population of the adult dairy cow is 400 for each designing farm;

奶牛场的规模为成乳牛400头的牛场一座；

The population of the Hakka accounted for only about 10 per cent of the total population of Penang Chinese.

客家人的人数，一直都只占华人人口的10%左右。

China is really between a rock and a hard place when it comes to its water sector.

在谈到水这个问题时，中国确确实实成了一个不好的地方。

The third act throws in more obstacles to place the protagonist between a rock and a hard place and then resolves all of the outstanding issues.

最后一幕则设置更多的障碍，将主角置于困境之中，并在最后解决所有的重大问题。

You were really between a rock and a hard place when you had to choose between your career and your relationship.

当你不得不在事业和感情之间做出选择时，真的是进退两难。