题目

What can we learn about the man?A. He is anxious to see his sister.B. He wrote to his sister last month.C. He is expecting a letter from his sister. 答案：【答案】C【解析】M: I haven't heard from my sister since last month.W:Don't worry, Charlie. Letters from the United States can be slow sometimes.此题为听力题，解析略。在氦气、氧气、氢气、赤铁矿、磷矿粉5种物质中，选择符合要求的物质填写在横线上．（1）工业炼铁的原料是______．（2）属于清洁能源的是______．（3）为延长灯泡使用寿命而充入的气体是______．