Use the reduced relative clauses to rewrite the following sentences
1. Macroeconomic performance is a central factor which affects the success or failure of nations.
2. The employees who work in the factory were carefully trained for two years.
3. The money that is spent on bridges is really great.
4. Most of the products which are made in this factory are exported to European countries.
5. The customers who use the products are satisfied with their quality and price.
6. The police never found the money which was taken away in the robbery