句型转换。

1. I have read today's newspaper. (改为否定句)

    I________  ________  today's newspaper.

2. His friend has bought some flowers. (改为否定句)

   His friend________ ________ ________ flowers.

3. I have bought some strawberries. (改为一般疑问句)

    ________ you ________ ________ strawberries?

4. Uncle Wang has worked in this factory for ten years. (改为一般疑问句)

    ________ Uncle Wang________ in this factory for ten years?

5. Have they gone shopping? (作否定回答)

   ________  ,they________ .

6. Has the play been on for ten minutes? (作否定回答)

   ________ ,it________ .

7. I have been to Changchun. (就画线部分提问)

    ________ ________  you________ ?

影响混凝土流动性的主要因素是（）。

A.混凝土单方用水量

B.混凝土的含砂率

C.水泥品种、用量与细度

D.粗骨料的级配