Complete the sentence with the correct part. While no one is looking, Frenchman Alain Robert jumps up an office building and starts to climb the wall. He hangs from balconies, crawls along ledges and grips the edges of the glass and concrete. There's no rope and no safety net - he's using only his bare hands! By the time he's halfway up, a crowd has gathered on the pavement below. After an hour, he reaches the top and the crowd sighs with relief. When Alain Robert climbs a structure,