Grammar: Present Perfect Present perfect is the action that happened and finished in the past, but it has the affection to the present. It starts and continues until now and there could be sustained action or state. The sentence structure is S. + have/has +V-ed. 过去发生并且已经完成的动作对现在造成影响或后果, 过去某一时间开始并一直持续到现在并且有可能还会持续的动作 或状态。 If you want to change the affirmative sentence into the question sentence, please put have or has in the front of the sentence.
Key vocabulary: words about the season, holiday, population, nature, environment, excellent Key phrases: on the one hand, on the other hand; three quarter, all year round, wake up Key points: words: spring, summer, autumn, winter phrases: on the one hand, on the other hand; three quarter, all year round, wake up grammar: Have you ever been to Singapore? Difficult points: understand the passage introduce the place use the grammar correctly