Six men have been 46.____ in a mine for seventeen hours. If they are not brought to the surface soon they may 47.____ their lives. However, rescue operations are proving 48.____. If explosives are used, vibrations will cause the roof of the mine 49.____ collapse. Rescue workers are therefore drilling a hole 50.____ the north side of the mine. They intend to bring the men 51.____ in a special capsule. If there had not been a hard layer of rock beneath the soil, they would have completed the job in a few hours. As it is, they have been drilling 52.____ sixteen hours and they still have a long way to go. Meanwhile, a microphone, 53.____ was lowered into the mine two hours ago, has enabled the men to 54.____ in touch with their closest relatives. Though they are running 55.____ of food and drink, the men are cheerful and confident that they will get out soon. They have been told that rescue operations are progressing smoothly. If they knew how difficult it was to drill through the hard rock, they would lose heart.1. ______A. trapB. trappedC. trappingD. traps