If we expect ________ much cleaner world, we should attract ________world’s attention to protect the world.

A. a; a                     B. a; /                 C. a; the               D. the; /

If we expect ________ much cleaner world, we should attract ________world’s attention to protect the world.

A. a; a        B. a; /        C. a; the        D. the; /

If we expect ________ much cleaner world, we should attract ________world’s attention to protect the world.

A．a; a          B．a; /         C．a; the          D．the; /

If we expect ________ much cleaner world, we should attract ________ world's attention to protect it.

1. A.
   a; a
2. B.
   a; 不填
3. C.
   a; the
4. D.
   the; 不填