Can an object have more than one centre of gravity?

R.Q is more than one in case of

For which of the hyperbolas, can we have more than one pair of perpendicular tangents?

Two distinct lines cannot have more than one point in common.Explain?

Two point objects of mass 1.5 gm and 2.5 gm respectively are at a distance 16 cm apart, the centre of gravity is at a distance 'x' from the object of mass 1.5 gm where 'x' is

Beryllium salts can never have more than 4 molecules of water of crystallisation, i.e., it can never achieve coordination number > 4 while other metal ions tend to have a coordination number of 6, e.g., [Ca(H_2O)_6]^(2+) . Explain.