问题 单项选择题

甲、乙两组冲锋队同时从A基地往B基地急行军,两个基地相距80千米,甲冲锋队步行每小时行4千米,乙冲锋队骑摩托车每小时行40千米,乙冲锋队到达B基地后,通知丙冲锋队立即从B基地向A基地出发,丙冲锋队步行每小时行5千米,乙冲锋队往返于甲、丙两冲锋队之间做联络工作,遇到一个冲锋队后立即返回,当甲、丙两冲锋队相遇时,乙冲锋队共行了多少千米( )

A.200

B.300

C.400

D.500

答案

参考答案:C

解析: 乙冲锋队到达B基地时,甲、丙两冲锋队相距:80-4×(80÷40)=72(千米),甲、丙两冲锋队相遇时,丙冲锋队行了:72÷(4+5)=8(小时),乙冲锋队共行了:40×8+80=400(千米)。故本题正确答案为C。

单项选择题

Comparisons were drawn between the development of television in the 20th century and the diffusion of printing in the 15th and 16th centuries. Yet much had happened between. As was discussed before, it was not until the 19th century that the newspaper became the dominant pre- electronic (61) , following in the wake of the pamphlet and the book and in the (62) of the periodical. It was during the same time that the communications revolution (63) UP, beginning with transport, the railway, and leading on through the telegraph, the telephone, radio, and motion pictures into the 20th-century world of the motor car and the air plane. Not everyone sees that process in (64) . It is important to do so.

It is generally recognized, (65) , that the introduction of the computer in the early 20th century, (66) by the invention of the integrated circuit during the 1960s, radically changed the process, although its impact on the media was not immediately (67) . As time went by, computers became smaller and more powerful, and they became "personal" too, as well as (68) , with display becoming sharper and storage (69) increasing. They were thought of, like people, (70) generations, with the distance between generations much (71) .

It was within the computer age that the term "information society" began to be widely used to describe the (72) within which we now live. The communications revolution has (73) both work and leisure and how we think and feel both about place and time, but there have been (74) view about its economic, political, social and cultural implications. "Benefits" have been weighed (75) "harmful" outcomes. And generalizations have proved difficult.

(66)是()

A.brought

B.followed

C.stimulated

D.Characterized

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