句型转换。

1.Open the door, please. (改为否定句)

   ________ ________ the door.

2.See you soon. (改为同义句)

   See you ________. 

3.He helps his mother do the housework every day. (改为否定句)

   He ________ ________ his mother do the housework every day.

4.I am packing my bookcase (书架). (对画线部分提问)

   ________ ________ paciking ________ bookcase?

5.There is and apple on the table. (改为否定复数句)

   There ________ ________ any apples on the table.

我国义务兵服役的期限是（）年？

A、1 

B、2 

C、3 

D、4