题目

阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。I went to the Changtang National Nature Reserve to observe Tibetan antelopes, which live on the 【1】 (plain) of Tibet, Xinjiang, and Qinghai. 【2】 (watch) them move slowly across the green grass, I'm struck by their beauty. However, they are being hunted, 【3】(illegal), for their valuable fur. The reserve is【4】 shelter for the animals and plants of northwestern Tibet.The 1980s and 1990s were bad times for the Tibetan antelope. The population 【5】(drop) by more than 50 percent. In order下列变化不属于化学变化的是（　　）A．燃放烟花B．食物腐烂C．剪贴窗花D．钢铁生锈