4、 has +been +过去分词?”3)教学重难点:1.Wordsandexpressionsinthisunit.2.Howtomakeconversationsfreelyusingthetargetlanguage.3.Mastertheusageofkeysentencesstructure.4)情感目标:1.Encouragestudenttoexpresstheiropinions..2.Toenablestudentstodevelopagoodhabitofrespectforo