【单选题】---Mum,_______ I watch TV? ---No. Unless your homework _______________.
【简答题】(see)______from the top of the tower at night, the city looks more beautiful.
【单选题】.--- Have you finished your homework? --- No. I ______ Good Voice of China on Zhejiang TV all day yesterday.
【简答题】(see) ______ from the top of the mountain, the sea looks really beautiful.
【简答题】PL/SQL中,单行注释用____,多行注释用____。