Long long ago mankind began to use tools. Throughout the world, you can still find the tools which were used over two million years ago. People made such tools by hitting one stone (36) another. By this means, they got pieces from one of the stones. These pieces of stone were always (37) on one side. People utilized them to (38) skin and meat from some animals that were dead, (39) to make other tools from wood. Mankind needed (40) use tools since, unlike other meat-eating (41) , say lions, they did not have sharp teeth. Tools greatly helped people obtain food more (42) .
Tools helped (43) human intelligence as well when human worked with them. The human brain became bigger gradually, and human beings began to invent a growing number of tools. The stone piece was one of the (44) tools that were used by people, and maybe it was (45) . Some scientists hold it was the key (46) huma
A. from
B. to
C. for
D. in
Long long ago mankind began to use tools. Throughout the world, you can still find the tools which were used over two million years ago. People made such tools by hitting one stone (36) another. By this means, they got pieces from one of the stones. These pieces of stone were always (37) on one side. People utilized them to (38) skin and meat from some animals that were dead, (39) to make other tools from wood. Mankind needed (40) use tools since, unlike other meat-eating (41) , say lions, they did not have sharp teeth. Tools greatly helped people obtain food more (42) .
Tools helped (43) human intelligence as well when human worked with them. The human brain became bigger gradually, and human beings began to invent a growing number of tools. The stone piece was one of the (44) tools that were used by people, and maybe it was (45) . Some scientists hold it was the key (46) huma
A. within
B. among
C. into
D. against
The development of toothpaste began as long ago as 3000/5000 BC in the ancient countries of China and India. According to Chinese history, Huang-Ti claimed different types of pain felt in the mouth could be cured by sticking gold and silver needles into different parts of the jaw and gum. h was theories such as these that led to the development of dental cream. During the years 3000/5000 BC, Egyptians made toothpaste using a recipe of powdered ashes of hooves of oxen, myrrh, powdered and burned eggshells and pumice. It is assumed that the ancient Egyptians used their fingers to rub the mixture onto teeth.
The tooth stick, the forerunner of the toothbrush, had not, as far as is known, been discovered at this time. From the records of the ancient countries of India, China and Egypt, it was the Greeks and Romans who developed and improved toothpaste and developed a leaden instrument for the extraction of teeth. They were also the first to bind loose teeth together and to sup
A. strengthening teeth
B. getting a foaming effect
C. reducing sensitivity
D. gums
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