题目

       V．短文改错 Dear editor, Some years ago, my hometown was used to be a beautiful place.                  66.                 Thick trees and grass can be seen all over the hills.                                      67.                 As time going by, people destroyed almost the whole                              68.                 forests grow more crops. To make matters worse, people let their                    69.             现有四种物质，选择相应物质的字母填空：A．干冰B．硬铝C．甲烷D．石油（1）被誉为“工业的血液”——   （2）可用作制造飞机——（3）可用于人工降雨——         （4）可燃冰的主要成分是——