We (a)   the dog to help us with hunting.

Top supermarkets are to ban many genetically (a)   foods.

State supporters (a)   radio advertisements to get their message across to voters.

These two chemicals (a)   with each other at a certain temperature to produce a substance which could cause an explosion.

The eggs of these fish (a)   to plant leaves.

(a)   promises to reduce the size of electronic components to one-millionth of a meter, or roughly 10 times the size of an atom.

Courses (a)   from cookery to computing.

When the (a)   fabric is contrasted with the natural one, the difference is very apparent.

A voltameter is a/an (a)   used for measuring quantity of electricity.