— Linda won first prize in the English speaking competition last week.
—Yes, she didn't let her teacher down.
A: make ... angry
B: make ... disappointed
C: make ... happy
2015年2月28日柴静上传的雾霾调查记录片《穹顶之下》24小时内的点击数破亿,影片指出烧煤炭是中国雾霾的主要污染源之一。以下发明中使煤炭得到广泛应用的是 ( )