Normality of 3-dimensional lattice polytopes

We construct examples of ample lattice polytope of dimension n⩾3 such that the n−2 times multiple of them are very ample but not normal. We also obtain two classes of normal 3-dimensional nonsingular lattice polytopes. One is a class of polytopes with relatively small internal polytopes. The other is that of polytopes which are the Minkowski sums with line segments.