Read the following passage and answer the given questions.

The strength of a nation is often measured not only by its economic output but by the stability, resilience, and well-being of its people. Economic growth stems from a combination of natural resources, infrastructure, governance, and, most critically, investments in human capital. Countries that prioritize education and healthcare lay the foundation for long-term prosperity.

A glaring truth in today’s global economy is that wealth alone cannot secure sustainable growth. Natural resource-rich nations may enjoy short-term revenue surges, but without strong institutions and a skilled, healthy workforce, such progress risks becoming fragile. Education equips individuals with the skills needed for innovation, adaptability, and competitiveness. Healthcare, in turn, ensures that citizens can contribute productively over the long term, reducing absenteeism and lowering the economic burden of disease.

For example, some resource-dependent nations have taken steps to diversify their economies by ________________ revenue into schools, training centers, hospitals, and public health programs. Angola, in recent years, has made efforts to invest in education and healthcare to reduce its dependency on oil exports. By enhancing human capital, it aims to strengthen productivity and attract investment in sectors beyond its primary industries. While challenges remain, such measures show the potential for transforming short-term gains into lasting national strength.

However, the global economic environment remains uncertain. Trade disruptions, fluctuating commodity prices, and geopolitical tensions can stall development plans, even in countries with ambitious social investment strategies. A grim example is when external shocks force governments to cut back on essential public spending, undermining years of progress in education and health sectors. The capacity to withstand such shocks depends heavily on diversified economies and robust fiscal planning.

National strength, therefore, is not built overnight. It requires consistent policies, transparent governance, and the vision to balance immediate economic needs with long-term development goals. By fostering a population that is educated, healthy, and capable of innovation, nations can ensure resilience in the face of global uncertainty.

In conclusion, economic growth flourishes when it rests on a solid social foundation. Investments in human capital — through education and healthcare — are not only moral imperatives but strategic economic decisions. Whether resource-rich or resource-poor, nations that prioritize these areas strengthen their position in the world and secure prosperity for future generations.

According to the passage, what is a key limitation of relying solely on natural resource wealth?