Use the reduced relative clauses to rewrite the following sentences

1. Macroeconomic performance is a central factor affecting the success or failure of nations.

2. The employees working in the factory were carefully trained for two years.

3. The money spent on bridges is really great.

4. Most of the products made in this factory are exported to European countries.

5. The customers using the products are satisfied with their quality and price.

6. The police never found the money taken away in the robbery.

* Mệnh đề quan hệ rút gọn (lược bỏ đại từ quan hệ)

- Mệnh đề mang nghĩa chủ động: đổi thành V-ing.

- Mệnh đề mang nghĩa bị động: bỏ tobe và giữ nguyên V(pp).