按给出的要求变换下列句子，要求每空限填一词。

1. This is a watch. (变为复数形式)

   __________ are some __________.

2. Can Cindy sing this song in Chinese?(作肯定回答)

   __________, __________ can.

3. This sweater is $28. (对划线部分提问)

    _________ __________ is this sweater?

4. He does his homework in the evening. (改为否定句)

    He __________ __________ his homework in the evening.

5. Tile biology class isn't boring. (改为同一句)

    The biology class __________ __________.