1. By 2020, birth rates in these counties should remain low and be steady.
2. By 2020, birth rates in these counties should be kept low and steady.
3. The third step is to ensure that both birth and death rates decline so as to ensure social security and economic freedom.
4. That's the year the population is projected to hit 400 million, though the numbers could change significantly depending on immigration and birth rates.
5. The land is rich in natural resources with much fertile ground for agriculture and a population that remains young with high birth rates.
6. First, as countries'birth rates decline they substitute child quality for child quantity.
7. This becomes obvious when we compare the birth rates of the most developed and the less developed countries.
8. As birth rates decline to low levels and adults live longer, the average age of a population increases and the proportion of older persons increases.
9. Officials have said it appears Shanghai is experiencing a " mini peak " in its birth rate compared to the low rates of recent years.
10. birth rates是什么意思
10. Throughout the nation, birth rates for boys and girls remain out of proportion.