单项选择题：外显子是指（） A．不被转录的序列 B．编码序列 C．被翻译的序列 D．被转录的序列

题型：单项选择题

依据《中华人民共和国环境噪声污染防治法》，城市人民政府应当在航空器起飞、降落的（）划定限制建设噪声敏感建筑物的区域。

A.两侧

B.周围

C.净空周围

D.区域

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题型：阅读理解

A grave of a man dating back to around 2300 BC was found by archaeologists in England On May 3, 2002. Buried with him were the tools of a hunter or warrior. There was a bone pin that may have been from a piece of clothing such as a leather coat. He carried a copper knife on his breast. The most amazing find was two gold earrings. That would have made him a man of distinction. Only a few centimeters from his head were two pots made of clay, tools and materials to make arrows, a bow and a dozen arrows for hunting and a second, smaller copper knife. Next to them lay a cushion stone, upon which the man could work metal.

His grave is the richest of any found from that period, because this man was buried with two gold earrings which are the oldest gold ever found in Britain (dated to 2470 BC). Besides, he was buried three miles from Stonehenge. Archaeologists tend to believe he was a member of a powerful class who might have organized the construction of Stonehenge.

Stonehenge was begun around 3000 BC. In about 2300 BC the huge stone circles were built. The biggest stone weighed approximately 20 tons. But the smaller blue stones, still weighing 4 tons on average, came from west Wales. It is not yet known how these were conveyed over a distance of 380 km. It is also a mystery how early man was able to construct Stonehenge without the use of modern construction machines and lorries.

He is an example of people who brought culture and new techniques from the European mainland to Britain. In terms of technical development people were going from the Stone Age to the Bronze Age and then to the Iron Age.

小题1:Which are not included in the things that are found in the grave of a man?

A．Tools, a bone pin, a bow and a cushion stone

B．A copper knife and two gold earrings.

C．Two pots, arrows and materials to make arrows.

D．some chicken and grains.小题2:The man buried in the grave might be ______ at that time.

A．A poor man

B．a kind-hearted man

C．a rich man

D．an ordinary man小题3:Why is the man buried in the grave called the "king of Stonehenge" ?

A．He was buried three miles from Stonehenge.

B．He had the oldest gold ever found in Britain.

C．He might be a member of a powerful class who might have organized the construction of Stonehenge.

D．All of the above.小题4:We can infer that _______ .

A．how Stonehenge was built

B．the King of Stonehenge was from France

C．Stonehenge was built through several ages

D．Stonehenge was built because of war

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题型：问答题

如图所示，正方形导线框ABCD之边长l=10cm，质量m=50g，电阻R=0.1Ω．让线框立在地面上，钩码质量m′=70g，用不可伸长的细线绕过两个定滑轮，连接线框AB边的中点和钩码，线框上方某一高度以上有匀强磁场B=1.0T．当钩码由图示位置被静止释放后，线框即被拉起，上升到AB边进入磁场时就作匀速运动．细绳质量、绳与滑轮间的摩擦和空气阻力均不计，g取10m/s²，求：

（1）线框匀速进入磁场时其中的电流．

（2）线框全部进入磁场所用的时间．

（3）在线框匀速进入磁场的过程中线框产生的电能占钩码损失的机械能的百分比．

（4）线框从图示位置到AB边恰好进入磁场时上升的高度．