What do you mean by three lows in low-low-low mode?

Low birth rate, low mortality rate and low natural growth rate.

It is the population growth model of developed countries.

There are three modes of population growth: 1 "high and low" mode, and (primitive/traditional) can be divided into primitive population growth mode and traditional population growth mode. Basic characteristics: high birth rate, high mortality rate and very/very low natural growth rate. The advantages and disadvantages of this model are really hard to say. Distribution: primitive society and primitive society in some parts of individual countries are limited by the natural environment. The natural growth rate is high in areas with superior natural environment and low in areas with poor environment. Compared with the original natural growth rate, slave society, feudal society and capitalist society increased slightly. The "high and low" mode (transitional type) occurred after the industrial revolution. Basic characteristics: high birth rate, low mortality rate and high natural growth rate. Benefits: increase social labor force, increase social wealth, promote social development and promote urbanization; Disadvantages: Up to now, the shortcomings have been obvious. Overpopulation has brought unprecedented pressure to social employment, and even caused a series of problems such as environmental pollution, ecological destruction, energy shortage and social instability. Agricultural society and most developing countries have a "low-low-low" model (modern model). The basic characteristics are: the birth rate began to drop obviously, and the death rate continued to drop and reached a low level. With the gradual narrowing of the gap between the two, the natural growth rate gradually decreased, and some countries even began to experience negative growth or zero growth. At present, major developed countries have entered. Benefits: Effectively alleviate the trend of rapid population growth and restore the regional population from a serious unbalanced state to a new basic balanced state. Disadvantages: With the development of "modernization", some countries have zero or negative population growth. This makes the social labor force insufficient, which is not conducive to industrial development and national economic development; Moreover, the aging population has increased the burden of social welfare and is not conducive to the financial construction of the country. Distribution: Developed countries and a few developing countries (1). Developed countries are "modern". (2) Developing countries are still in a "transitional type". (3) The type of world population reproduction is "transitional".