解?$：(1)$?原式?$=\frac {1}{3}+0.3-\frac {1}{3} $?
?$=0.3 ； $?
?$(2)$?原式?$=\sqrt {6}-\frac {1}{2} \sqrt {2}-2 \sqrt {6}-\frac {2}{3} \sqrt {6} $?
?$=-\frac {5}{3} \sqrt {6}-\frac {1}{2} \sqrt {2} ；$?
?$(3)$?原式?$= {[\sqrt {3}+\sqrt {5}+\sqrt {6}-(\sqrt {3}-\sqrt {5}+\sqrt {6})]·} $?
?$ {[\sqrt {3}+\sqrt {5}+\sqrt {6}+(\sqrt {3}-\sqrt {5}+\sqrt {6})] } $?
?$= 4 \sqrt {5}(\sqrt {3}+\sqrt {6}) $?
?$= 4 \sqrt {15}+4 \sqrt {30}$?
