练习材料：
任务配置：L0+L1+L4
知识笔记：
2. 音标（L1)
双元音回顾：[eɪ] [aɪ] [ɔɪ] [əʊ] [aʊ] [ɪə] [eə] [ʊə] 由前元音滑向后元音，后元音是三个含糊的短元音[ɪ] [ʊ] [ə]。
课中的单词：
[eɪ] : Escape changed blazing gates came gray
[aɪ] : rifle Lights inside driver eyes
[ɔɪ]
[əʊ] : clothes over shoulder boldly moment blow drove
[aʊ] : down shouting out ground
[ɪə] : hear here obviously clear near
[eə] : there hair
[ʊə]
练习感悟：双元音的滑动过程要自然还要到位，而且前元音要饱满，后元音要正确。
