И. А. Курбасова Е. И. Силантьева

That the electric railways do not pollute air is of great significance for people. To, что электрические железные дороги не загрязняют воздух, имеет огромное значение для людей (придаточное предложение подлежащее).

1. One of the problems for monorail engineers is how silent operation of monorail vehicles can be provided. 2. That electrification is of great importance to any country is clear to everyone. 3. The question discussed was whether diesel or electric traction would be cheaper to use on industrial tracks. 4. Whether changes will be made in the design of the locomotive is not decided yet. 5. The idea is that power sources should be installed in­side the vehicles. 6. What sections of the BAM Railway were to be electrified had been decided before the construc­tion of the line began. 7. How safety can be ensured at the atomic power plants is not a simple problem.