Main Cause for the High Growth of Population
The main cause for the high growth of our population is the decline of death rate.
Explanation:

• Rise in death rate: This option suggests that the increase in population is due to a higher death rate. However, this is not accurate as a rise in death rate would actually result in a decrease in population growth.


• Decrease in birth rate: This option suggests that the decrease in birth rate is the main cause for the high growth of population. However, a decrease in birth rate would actually lead to a decrease in population growth.


• Decline of death rate: This option correctly identifies the main cause for the high growth of population. A decline in death rate means that fewer people are dying, leading to a higher overall population growth.


• None of these: This option suggests that none of the given options are the main cause for the high growth of population. However, as explained above, the decline of death rate is indeed the main cause.

In conclusion, the decline of death rate is the main cause for the high growth of our population.

Explanation:

The main cause for the high growth of our population is the decline in death rate. Let's understand this in detail:

1. Decline in Death Rate:
- The decline in death rate refers to a decrease in the number of deaths per 1,000 individuals in a population over a given period of time.
- This decline is primarily due to advancements in medical science, improved healthcare facilities, better sanitation, and increased access to clean drinking water.
- Medical breakthroughs such as the development of vaccines, antibiotics, and other life-saving drugs have significantly reduced mortality rates.
- Improved healthcare infrastructure and facilities have ensured better healthcare services to people, leading to a decrease in deaths caused by diseases and infections.
- The provision of clean drinking water and sanitation facilities has reduced the spread of waterborne diseases, further contributing to a decline in death rates.

2. Impact on Population Growth:
- A decline in death rate has a direct impact on population growth. When the number of deaths decreases, the overall population increases.
- As more individuals survive to reproductive age, they can contribute to the growth of the population by having children.
- This results in a higher birth rate, which further contributes to population growth.

3. Other Factors:
- While the decline in death rate is the main cause of population growth, it is important to note that other factors also play a role.
- These include factors such as increased fertility rates, cultural and social norms, economic conditions, availability of resources, and government policies related to population control.

Conclusion:
In conclusion, the decline in death rate is the primary cause of the high growth of our population. Advancements in medical science, improved healthcare facilities, better sanitation, and access to clean drinking water have all contributed to a decrease in mortality rates, resulting in a higher population growth rate.