Before the world had standardized time, there was only localizedtime. Every city in the world told time differently, using the __1__ of the sun at their location to do so. This led to the creation of primitive clocks called sundials, which were the first clocks used by humans. When analogclocks __2__, it made telling time easier. But the telling of time remained relative, and there was no standard time for the start or end of a day. This didn’t pose a problem until people started traveling between cities and creating __3__ became a logisticalnightmare.
Many scientists had tried to persuade governments to start using a standard way to tell time. One suggested method was Greenwich Mean Time (GMT). GMT is __4__ by the sun crossing the Prime Meridianat the Royal Observatoryin Greenwich, England. The Prime Meridian is an __5__ line that runs from north to south and splits the world into two halves. When the sun is at its highest __6__, exactly above the Prime Meridian, this means it is 12:00 noon at Greenwich. Sailors from Britain had been using this method to calculate time on __7__ since the 18th century by keeping a mechanical clock set to the Prime Meridian line.
As Britain’s railway and communication systems grew, the need for a standardized time system increased. Since 72% of the world’s trade __8__ viaships that used the Prime Meridian line, GMT became the standard time across the world. However, since GMT uses the sun, it’s not always __9__. Many countries have gradually __10__ Coordinated Universal Time (UCT), which is measured by an atomicclock and is more accurate.
Regardless of which time zone you are in, it makes life easier to have one method to measure time that everyone agrees on. Thanks to GMT, you can easily tell what time it is in Taiwan while you are visiting friends in London!
(A) point
(B) determined
(C) reliable
(D) position
(E) imaginary
(F) voyages
(G) came around
(H) adopted
(I) took place
(J) schedules
