题目内容
The invention of both labor-saving tools and tools of intelligence is rarely accidental. Instead, it is usually the product of human need; (1) is truly the mother of invention. People usually devise tools to (2) for natural deficiencies. For example, people invented weapons to defend (3) from physically superior (4) . But (5) is only one incentive for inventions. People also invent (6) tools to (7) certain established tasks more efficiently. For instance, people developed the bow and arrow from the (8) spear or javelin in order to shoot (9) and strike with greater strength.(10) civilizations developed, greater work efficiency came to be demanded, and (11) tools became more (12) . A tool would (13) a function until it proved (14) in meeting human needs, at which point an improvement would be made. One impetus for invention has always been the (15) for speed and high-quality results—provided they are achieved (16) reasonable costs. Stone pebbles were sufficient to account for small quantities of possessions, (17) they were not efficient enough for performing sophisticated mathematics. However, beads arranged systematically evolved into the abacus. The (18) of this tool can be (19) to the development of commerce in the East around 3000 B.C. and the abacus is known (20) by the ancient Babylonians, Egyptians, Chinese, etc.. 11（）
查看答案
搜索结果不匹配？点我反馈
更多问题
What made the new immigrants generally different from the "sojourners" Chinatowns also work as forces for sustaining______.
Motorways are, no doubt the safest roads in Britain. Mile (21) mile, vehicle for vehicle, you axe much (22) likely to be killed or seriously injured than on an ordinary road. On (23) hand, if you do have a serious accident on a motorway, fatalities are much more likely to (24) than in a comparable accident (25) on the roads.Motorways have no (26) bends, no roundabouts or traffic lights and (27) speeds are much greater than on other roads. Though the 70 mph limit is (28) in force, it is often treated with the contempt that most drivers have for the 30 mph limit applying in built up areas in Britain. Added to this is the fact that motorway drivers seem to like traveling in groups with perhaps (29) ten meters between each vehicle. The resulting horrific pile-ups (30) one vehicle stops for some reason—mechanical failure, driver error and so on—have become all (31) familiar through pictures in newspapers or on television. How (32) of these drivers realize that it takes a car about one hundred meters to brake to a stop (33) 70 mph Drivers also seem to think that motorway driving gives them complete protection from the changing weather. (34) wet the road, whatever the visibility in mist or fog, they (35) at ridiculous speeds oblivious of police warnings or speed restrictions (36) their journey comes to a conclusion.Perhaps one remedy (37) this motorway madness would be better driver education. At present, learner drivers are barred (38) motorways and are thus as far as this kind of driving is (39) , thrown in at the deep end. However, much more efficient policing is required, (40) it is the duty of the police not only to enforce the law but also to protect the general public from its own foolishness. 26（）
大客车驾驶人在发生交通事故时首先要保护自己，其次保护乘车人。
Which of the following is NOT the reason that the man wanted to buy a stereo
微信支付 
支付宝支付