句型转换
I can borrow the books from the library twice a week. (就划线部分提问)
               can you borrow the books from the library?
Which is your favorite subject ? (同义句改写) 
Which subject do you  ________ ________?
He seldom goes to Shanghai by train. (改为一般疑问句)。
        he seldom         to Shanghai by train?
You can’t talk so loudly in class. (改为祈使句)。
                 so loudly in class
There are some boys on the playground. (改为否定句)。
There               boys on the playground.