The TV program has begun since half an hour ago（同义句）The TV program_____ _____ _____ _____half an hour最后一个空是for吧?那前三个是什么?这是我们学校发的预习题,所以麻烦讲解清楚一点~

The TV program has begun since half an hour ago（同义句）The TV program_____ _____ _____ _____half an hour最后一个空是for吧?那前三个是什么?这是我们学校发的预习题,所以麻烦讲解清楚一点~
The TV program has begun since half an hour ago（同义句）
The TV program_____ _____ _____ _____half an hour
最后一个空是for吧?那前三个是什么?这是我们学校发的预习题,所以麻烦讲解清楚一点~

The TV program has begun since half an hour ago（同义句）The TV program_____ _____ _____ _____half an hour最后一个空是for吧?那前三个是什么?这是我们学校发的预习题,所以麻烦讲解清楚一点~
has been on for