题目

互为同素异形体的一组物质是（ ） A . 金刚石和石墨 B . H和 H C . CH3CH2OH和CH3OCH3 D . CH4和C2H6 答案：A根据语境及所给图片提示写出所缺单词。（1）Four are at the station．（2）Those are in the school．（3）There isn't any at home.（4）Eat some ,please.（5）Do you like ?