按要求改写下列各句，每空一词。
1. My pants are fifty dollars. (改为一般疑问句)
    _____ _____ pants fifty dollars?
2. The black socks are 2 dollars.(对画线部分提问)
    _____ _____are the black socks?
3. The store sells apples.(改为否定句)
    The store _____ _____ apples.
4. Her sweater is yellow.(对画线部分提问)
    _____ _____ is her sweater?
5. Are his shoes black?(作肯定回答)
    Yes, _____ _____.