B. Read the text and answer the following questions.
 

In a speech at the 90th Science Congress, internationally acknowledged scientist and former Indian president Mr APJ Abdul Kalam mentioned a very important aspect of this mankind's future energy crisis. He pointed out that the era of wood and bio- mass has almost come to an end. The age of oil and natural gas would soon be over within the next few decades. Massive burning of world's coal reserves may lead to a worldwide ecological disaster because coal burning emits the highest amount of carbon in the atmosphere. So according to Kalam, the only solution that mankind can look to is the massive use of solar energy in future because it has some advantages over other forms of renewable energies.

Now, why has Kalam put so much importance to the issue of energy? The energy sources have always been a major factor of change throughout history. The world's petroleum consumption has increased from 3 billion barrels annually in 1930 to 37 billion barrels annually today. In the next quarter century, the world's population is expected to be about 8 billion which is 30 percent higher than today. Developing countries will grow their economies about two times faster than industrialised countries. Global economic growth is expected to continue at 3 percent per year. Consequently, the global demand for energy will grow at about 1.7 percent per year on an average. It indicates a 50-percent rise of energy consumption by 2030. If the world's daily petroleum consumption is 100 million barrels now, it will rise to 150 million barrels by that time. The present reserve of hydro-carbon energy resources is limited and it will not be sufficient to meet the future energy challenges of the world. Hence, leading 

gfindustrial countries have taken initiatives to use alternative energy sources mainly known as green or renewable energy sources. The bottom line of Kalam's speech indicates the concern of mankind in the 21st century.

Questions
1. What is the scientist Kalam concerned about?

2. Why do you think the massive burning of coal may lead to an ecological
disaster?

3. What do you mean by the potential danger of nuclear energy?

4. What according to Mr Kalam is the solution of future energy crisis?

5. Why does Mr Kalam put so much importance on the issue of energy?

6. Why does Mr Kalam put much importance on solar energy?

C. Make sentences using the substitution table.