1. The fact can not be igored that many people are still going hungry.
2. In recent years, the grain yield has been reduced by the climate change.
3. The population should be controlled to deal with the food crisis.
4. The grain yield is greatly influenced by the rapid climate change.
5. The food crisis is mainly caused by the rapidly rising population and limited cultivated land.
6. We are more concerned about the energy.
7. I hope that more and more people will be aware of the importance of energy conservation.