He ________ there is no air or water on the moon.

1. A.
   heard
2. B.
   hearing
3. C.
   hear
4. D.
   is hearing

He ________ there is no air or water on the moon.

[　　]

There is no air________water on the moon．

1. A.
   so
2. B.
   but
3. C.
   and
4. D.
   or

There is no air ________ water on the moon, ________?

1. A.
   and; is there
2. B.
   or; isn't there
3. C.
   or; is there
4. D.
   and; isn't there