1.   stream   brook   river   pond   Hint Half-n-half Clue   2.   low   now   how   cow   Half-n-half Clue   3.   water   pond   lake   pool   Half-n-half Clue   4.   trumpet   flute   bugle   guitar   Half-n-half Clue   5.   mouse   man   tree   paper   Half-n-half Clue   6.   Earth   Mars   Pluto   Moon   Half-n-half Clue   7.   aluminum   iron   carbon   copper   Half-n-half Clue