Определите функции инфинитива и переведите предложения на язык: 1. to know the quantity of energy present in a body is very important. 2. to escape the pull of the sun a velocity of 16.6 kilometers per second is required. 3. in all the methods of arc welding, an electric arc is struck between an electrode and the parts to be welded. 4. the atom is a mighty force that is to be of great assistance to man. 5. the purpose of neutron diffusion theory is to determine the behavior of neutrons produced by nuclear fissions. 6. the dog laika was the first living creature to fly aloft in an artificial earth satellite. 7. one must know beforehand whether sufficient current will flow through the circuit to perform the work to be done. 8. watching one of our cosmonauts on television, we could see a growth of beard appearing on his face, so fine was the quality of the image received on the earth. 9. the soil in yakutia proved to be very rich in mineral deposits. 10. this material is sure to help you in your work.