\[\boxed{\mathbf{34}\mathbf{.}}\]
\[1)\ \sqrt[3]{5^{3} \bullet 7^{3}} = \sqrt[3]{5^{3}} \bullet \sqrt[3]{7^{3}} =\]
\[= 5 \bullet 7 = 35\]
\[2)\ \sqrt[4]{11^{4} \bullet 3^{4}} = \sqrt[4]{11^{4}} \bullet \sqrt[4]{3^{4}} =\]
\[= 11 \bullet 3 = 33\]
\[3)\ \sqrt[5]{(0,2)^{5} \bullet 8^{5}} =\]
\[= \sqrt[5]{(0,2)^{5}} \bullet \sqrt[5]{8^{5}} = 0,2 \bullet 8 = 1,6\]
\[4)\ \sqrt[7]{\left( \frac{1}{3} \right)^{7} \bullet 21^{7}} =\]
\[= \sqrt[7]{\left( \frac{1}{3} \right)^{7}} \bullet \sqrt[7]{21^{7}} = \frac{1}{3} \bullet 21 = 7\]