Experts predict nine billion people will live on our planet by 2050. They say by that time demand for food will be two times what it is now. Officials are worried about that prediction because many people already suffer from a lack of food. More than 800 million people go to bed hungry. _________________________专家预测2050年将有90亿人居住在地球上,并称到那时食物的需求量将是现在的两倍.政府官员对此预测表示担忧,因为现在已经有不少人挨饿,8亿多人饿着肚子睡觉._______________________
