Автор - Танюшка1208
1. You must use a power-driven machine to perform different operations with metal.
2. The investigation performed by the engineer is very important.
3. The test performed is very complex.
4. Having performed experiment switch off the equipment.
5. When performing experiments be careful.
Ответ:
1. To perform
2. Performed
3. Performed
4. Performed
5. When performing
Объяснение: