练习材料：Lesson 4 An exciting trip
I have just received a letter from my brother, Tim. He is in Australia. He has been there for six months. Tim is an engineer. He is working for a big firm and he has already visited a great number of different places in Australia. He has just bought an Australian car and has gone to Alice Springs, a small town in the centre of Australia. He will soon visit Darwin. From there, he will fly to Perth. My brother has never been abroad before, so he is finding this trip very exciting.
任务配置：L0+L4
知识笔记：
舌齿、浊辅音/ð/发音方法
1）首先将舌尖微微伸出略微露出齿外，置于上下门齿之间，舌身成扁平。
2）气流从舌齿间的窄缝中泄出，同时声带震动发出/ð/这个音。
注意：/ð/是舌齿、浊辅音，舌尖和下齿之间的气流通道非常窄小。发这个音主要是舌尖与上齿之间的摩擦，所以千万不要紧紧咬住舌尖，只要轻轻咬一咬就行了！
练习感悟：这篇文章简单，实际上还是有发音啊，断句啊这些可以学习的地方能找
