dual space W* of W can naturally identified with linear functionals

The first dual mission in space started in 1963, space craft: Vostock 5-6 sent by the USSR

DUAL table

Yes, Death Knights are able to dual wield in beta, and will also be able to in live WotLK. They can use 2 handed axes, 2 handed swords, 1 handed axes, 1 handed swords, and dual wield the one handed weapons. They CANNOT use shields.

A dual layer DVD has more space compared to a single layer DVD. Instead of holding 4.7GB, a dual layer DVD can hold over 8GB. Aside from more space, they also tend to read faster than single layer ones.