(3) Looking at the map, the death rate in Germany is higher than the birth rate, and the birth rate depends on people's concept of fertility, while the death rate depends on the proportion of the elderly. Germany has a high level of economic development, high standard of living and medical and health care, prolonged life expectancy and a high proportion of the elderly, so the mortality rate is high.
So the answer is: (1) Niger; The birth rate is high and the population is growing rapidly. Impact: The pressure of economy, employment, resources and environment has increased, resulting in a decrease in accumulation, a slowdown in economic development and a slow rise in people's living standards. Measures: family planning.
(2) The level of economic development, especially the level of productivity, plays a decisive role in population growth. However, developing countries and regions have low productivity and great demand for labor, which leads to high birth rate.
(3) Germany; The economy is developed, the living standard and medical and health level are high, the average life expectancy of the people is prolonged, and the proportion of the elderly population is high, so the population mortality rate is high.