2. Revolving surface f (y, +-√ x 2+z 2) = 0.

3. Cylinder Y 2/B+Z 2/=1; x^2/a-y^2/b= 1； x^2=2pz

conicoid

1. ellipsoid x 2/a 2+y 2/b 2+z 2/c 2 =1.

2. Parabola X 2/2p+Y 2/2q = Z (P, q have the same sign).

3. univalent hyperboloid X 2/A 2+Y 2/B 2-Z 2/C 2 = 1.

Bilobal hyperboloid x 2/a 2+y 2/b 2-z 2/c 2 =-1.