由于不方便打符号,用汉字：
The old man came( in为降调）in,asked for a cup of( tea升降都行)tea and sat down at a (table降调 ) table.
2.Would like a cup of (tea为升调 )tea or a glass of(milk为降调 )milk?
3.When my mother came (我认为back读升读降都行,看说话人的口气 )back,I was drawing a ( picture降调)picture.
听一听英语的对话,你可以感受出什么是升调什么是降调的