A、Decreasing the stock for food. B、Adjusting the food production scale. C、Cultivating more lands to grow. D、Encouraging speculat

An international aid group is calling for an overall check of the world’s food system, saying prices for main food such as corn will double in the next 20 years. London-based Oxfam released a report Tuesday saying demand for food is expected to rise 70 percent by 2030, as climate change, lower crop yields and rising energy prices pressure food supplies.
    The group says those hardest hit will be the poor, who spend as much as 80 percent of their income on food. The report recommends addressing the problem by boosting food reserves, ending the use of food crops in biofuels, and ending speculation in worldwide food markets. It also calls for a shift away from large-scale commercial food producers to smaller local growers.
3 How many percent of food demand will be increased by 2030?
4 What does the report suggest to control the food price?