Some animals can even see things ____________ in the dark.

   A. bad           B. badly            C. clear          D. clearly

 Battery-operated slippers are used ______ seeing in the dark.

A. to              B. as              C. by             D. for

 Battery-operated slippers were used _________ seeing in the dark.

     A. of         B. by              C. at                     D. for

 Some animals can even see things_______ in the dark.

A. bad   B. badly   C. clear    D. clearly