I think ________ good knowledge of English is ________ great help when you are traveling around the world.

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

I think ___ good knowledge of English is ___ great help when you are traveling around the world.

A. X，a     B. a，a     C. a，the     D. a，x

I think ___ good knowledge of English is ___ great help when you are traveling around the world.

A. X，a     B. a，a     C. a，the     D. a，x

I think ________ good knowledge of English is ________ great help when you are traveling around the world

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

I think ________ good knowledge of English is ________ great help when you are traveling around the world.

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

I think ________ good knowledge of English is ________ great help when you are traveling around the world.    

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

I think _________ good knowledge of English is _________ great help when you are traveling around the world.

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

I think ________ good knowledge of English is ________ great help when you are traveling around the world.