水蜜桃是由（   ）发育而来的

A．子房壁

B．子房

C．受精卵

D．胚珠

按要求完成句子。

1.There are two English books and a dictionary on the desk.( 改为同义句) 

There                on the desk.

2.There are some photos on the wall.( 改为否定句) 

There                   photos on the wall.

3.There is a dictionary on Li Lei's desk.( 改为一般疑问句,并作肯定回答) 

-                  a dictionary on Li Lei's desk? 

-Yes,                 .

4.There are some flowers on our teacher's desk.( 就画线部分提问) 

         on your teacher's desk?

5.Daming's friend is in front of the tree.( 就画线部分提问) 

                  Daming's friend?