$\star$ Classify the surface (a) $x^{2}+4 y^{2}+9 z^{2}=1$ (b) $y=2 x^{2}+z^{2}$ (c) $y^{2}=x^{2}+2 z^{2}$ (d) $x^{2}-6 x+4 y^{2}-z=0$ (e) $x^{2}+2 z^{2}=1$

Step 1 ：\(x^{2}+4 y^{2}+9 z^{2}=1\) is an \(\boxed{\text{ellipsoid}}\)

Step 2 ：\(y=2 x^{2}+z^{2}\) is an \(\boxed{\text{paraboloid}}\)

Step 3 ：\(y^{2}=x^{2}+2 z^{2}\) is an \(\boxed{\text{hyperboloid}}\)

Step 4 ：\((x-3)^2 + 4y^2 - z = 9\) is an \(\boxed{\text{elliptic paraboloid}}\)

Step 5 ：\(x^{2}+2 z^{2}=1\) is an \(\boxed{\text{elliptic cylinder}}\)