At around 1.65 million years ago, another early human, Homo ergaster, started to create tools in a slightly different fashion. This so-called Acheulean tradition was the tool-making technology used for nearly the entire stone Age, and practiced until i00,000 years ago. Acheulean tools, such as hand axes arid cleavers, were larger and more sophisticated than their predecessors. They may have been status symbols as well as tools.
Homo ergaster first appeared in Africa around 2 million years ago and in many ways resembled us. Though they had brow ridges, they had lost the stoop and long arms of their ancestors. They may have been even more slender than us and were probably well-adapted to running long distances. Some experts believe that they were the first to sport largely hairless bodies, and to sweat, though anther theory puts our hairlessness down to an aquatic phase.
One famous example of a more modern looking early human is the Turkana boy, a teenager when he d
A. were largely hairless
B. had lived in an aquatic phase
C. had long arms of their ancestor
D. were well-adapted to running long distances
It was probably around 3,000 years ago that people first began making things to help them measure the passage of time. Having noticed that shadows move around trees as the sun moves across the sky, someone drew a circle and put a stick in the center. As the sun passed overhead, people could tell which part of the day it was by noticing which mark on the circle the shadow fell across. These circles were called "sundials". latter, they were made of stone and metal to last longer.
Of course, a sundial did not work at night or on cloudy days, so men kept inventing other ways to keep track of time. After glass blowing was invented, the hourglass came into use. An hourglass is a glass container for measuring time in which sand moves slowly from the top half to the bottom in exactly one hour. The hourglass is turned over every hour so the sand could flow again.
One of the first clocks with a face and an hour hand was built for a king of France and placed in the
A. answer phone calls
B. say your name
C. start a small machine
D. cook different food
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