Read the following passage and think of a word which best fits each space

Section 1:
Read the following passage and think of a word which best fits each space. Use only ONE
word for each space.
Getting from place to place has been a challenge for humans (1) ______ the beginning of man’sexistence. Not only (2)______ peoplestruggle with the actually physical problems of travel, but they also need to know the right direction to go. In one’s own little part of the world, this may have been relatively easy, but, as humans expanded further and further, it became necessary to determine how to get from one 4 place to (3) ______ and back again. Paths, roads, and trails made journeys easier, and the creation of maps transmitted this knowledge to others. (4) ______, once humans pushed onto the vast oceans, there were (5) ______ roads or accurate maps. The compass, showing the magnetic north, was a great, yet imperfect, aid. Latitude could be measured by sun angles, but (6) ______ the perfection of timepieces in the 19th century, it was almost impossible to measure longitude. Fortunately, today there is a device which allows people easily to find their position no matter (7) ______ they are: the Global Positioning System (GPS). The Global Positioning System (8) ______ of a series of twenty - four satellites in geosynchronousorbit around Earth at an altitude of 12,500 miles. These satellites are in fixed positions, so, by reading the (9) ______ from three of them, a person holding a GPS receiver can know exactly where he is. The GPS receiver synchronizes its clock with (10) ______of the satellites’ atomic clocks