··改为含宾语从句的复合句Why does not he look happy?I do not know.The moon moves round the earth.My sister told me

I do not know the reason that he doesn't look happy.
My sister told me that the moon moves round the earth.

I don't know the reason that he looks happy.
My sisiter told me that the moon moves round the earth.

I don't know the reason that he looks happy.
My sisiter told me that the moon moves round the earth.

I do not know why he looks happy.
My sister told me the the moon moves round the earth.