Fill in the blanks with the right words (namely, types of welding). 1. …welding is successfully used in manufacture of small elements of electric circuits. 2. heat is not used in … welding. 3. … is widely used in aerospace industries. 4. vibration is used in …welding. 5. plastic deformation is the basic principle in … welding. 6. … welding is impossible without pressure and high temperature. 7. in … welding one of the parts being welded revolves.