句型转换
The bag is filled with books．(改为同义句)
The bag ________ ________ ________ books．
If there is no air, we can't live．(改为同义句)
________ air, we can't live．
It's very hot．Don't close the door．(改为同义句)
It's very hot．Please ________ the door ________．
Elephants walk on tiptoe．(对划线部分提问)
________________________________
It takes about three days to travel from the Earth to the Moon by rocket．(对划线部分提问)
________ elephant is ________ useful animal．
A．
An; a
B．
The; an
C．
An; an
D．
The; a
The room is dirty．You must keep it ________．
to clean
clean
cleaning
cleaned
He went out without a raincoat ________ an umbrella．
and
but
or
with
Fish sleep ________ their eyes ________．
with; opened
without; close
with; open
without; open
There is ________ UFO in the sky．
an
a
/
some