问题 选择题

图中a为晨昏线, c为经线,b为c线上地球自转线速度最大的点。读图回答问题。

小题1:当a、c两线重叠时,下列叙述正确的是

A.北京和海口昼夜等长

B.北极圈及其以北有极昼现象

C.b地正午太阳高度角达一年中最小值

D.此时地球位于公转轨道的近日点附近小题2:下面四幅图中,能正确表示b地水平运动物体方向的是

答案

小题1:A

小题2:C

本题考查地球运动。

小题1:当a(晨昏线)、c(经线)两线重叠,日期为春(秋)分日,此时全球各地昼夜等长。b地自转线速度最大,应位于赤道上,在春(秋)分日正午太阳高度应达一年中最大值,而地球位于公转轨道近日点附近为1月初。

小题2:由于b位于赤道上,无地转偏向力,物体无偏转现象,运动方向应保持初始方向。

单项选择题
单项选择题

When an invention is made, the inventor has three possible (1) of action open to him: he can give the invention to the world by publishing it, keep the idea (2) , or patent it.

A (3) patent is the result of a bargain (4) between an inventor and the state, hut the inventor gets a limited period of monopoly and publishes full details of his invention to the public after that period (5) .

Only in the most exceptional circumstances (6) the lifespan of a patent (7) to alter this normal process of events.

The longest extension ever (8) was to Georges Valensi; his 1939 patent for color TV receiver circuit was extended until 1971 because for most of the patent’s normal life there was no color TV to (9) and thus no hope for reward for the invention.

Because a patent remains permanently (10) after it has terminated, the shelves of the library attached to the (11) office contain details of literally millions of ideas that are free for anyone to use and, if (12) than half a century, sometimes even repatent. Indeed, patent experts often advise anyone (13) to avoid the high cost of conducting a search through (14) patents that the one sure way of violation of any other inventor’s right is to plagiarize a dead patent. Likewise, because publication of an idea in any other form (15) invalidates further patents on that idea, it is traditionally (16) to take ideas from other areas of print. Much modern technological advance is (17) on these presumptions of legal security.

Anyone closely (8) in patents and inventions soon learns that most "new" ideas are, in fact, as old as the hills. It is theft reduction to commercial practice, either through necessity or dedication, or through the availability of new technology, (19) makes news and money. The basic patent for the theory for magnetic recording dates back to 1886. Many of the original ideas behind television originate (20) the late 19th and early 20th century. Even the Volkswagen rear engine ear was anticipated by a 1904 patent for a cart with the horse at the rear.

13()

A.wished

B.refusing

C.refused

D.wishing