A:what was she doing
B:what is she doing
C:what she was doing
D:what she is doing
我们希望,我们祈盼——
让____的孩子,
有一张____,____,
不被____掀翻!
有一间____,____,
免遭____击穿!
和我们一样____,
和我们一样____……
东北地区划分为三大农业生产区域的依据是( )
青蛙的发育是( )。