①This song sounds very pleasant.Let's go upstairs and see who_is_singing(谁在唱歌)．

　　②She is_always_thinking_of(总是想着) how she can do more for the people.

　　③The plane is_taking_off(就要起飞了)．Please fasten your seat belt.

　　三、现在完成时

　　1．表示动作发生在过去，但对现在造成一定的影响或结果，常与already，yet，recently，never，before，so far，up to now等连用。

　　I have already made a plan for my study ahead of time.

　　我已经提前制定了学习计划。

　　2．表示动作从过去某一刻开始一直持续到现在，并有可能继续持续下去，常与表示一段时间的状语连用。

　　She left school three years ago and has worked as a teacher ever since.

　　她三年前毕业，从那时起一直当老师。

　　3．在"This/It is the first/second....last time＋that从句"与"This/It is the ＋序数词"或"形容词最高级＋名词＋that从句"中，从句中的谓语动词要用现在完成时。

　　This is the first time that I have been here.

　　这是我第一次来这里。

　　4．在时间或条件状语从句中，现在完成时可代替将来。

　　I won't believe it until I have seen it with my own eyes.

　　直到我亲眼见到才相信。

　　[即时训练3]

　　完成句子

　　①Great_changes_have_taken_place(发生了很大变化) in China in the past five years.

　　②It's the_best_film_I_have_ever_seen(我看过的最好的影片)．It's worth seeing a second time.

　　③I'll return the book to you as soon as I have_finished_reading_the_book(读完这本书)．

四、一般将来时