1. The flea starts from a straight line at 0: 00, jumps to the right for the first time 1 unit, jumps to the left for the second time by 2 units, jumps to the right for the third time by 3 units, and jumps to the left for the fourth time by 4 units ... It regularly jumps in turn, and when it jumps to100th, how many units is the distance from its landing point to zero?

2. A subgrade survey team walked five and two-thirds kilometers west on the first day, five and one-third kilometers west on the second day, four and one-half kilometers west on the third day and four and a half kilometers west on the fourth day. How many kilometers has the subgrade survey team been walking? In what direction is the final survey team at the starting point? How many kilometers apart?