琥珀是() A.晶质体 B.有机宝石 C.非晶质 D.化石

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问题:

琥珀是()

A.晶质体

B.有机宝石

C.非晶质

D.化石

考点:宝石学宝石学题库
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古希腊民主政治建立的有利条件不包括(    )

A.宽松自由的社会环境

B.较早接受平等互利的观念

C.小国寡民的城市国家

D.没有发生大规模战争

题型:多项选择题

肾结石体外冲击波碎石后,发现有残存较大结石颗粒,再次冲击碎石间隔时间不得少于()

A.7天内

B.10天

C.14天

D.2~3天

E.7天

题型:多项选择题

甲数是乙数的3倍,甲、乙两数的最大公因数是乙数。[ ]

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从Windows环境进入DOS方式后,返回Windows环境的命令为( )。

A.QUIT

B.WIN

C.EXIT

D.ESC

题型:多项选择题

An Event of Imagination


The year is 2094. It has been announced that a comet is heading towards the Earth. Most of it will miss our planet, but two pieces will probably hit the southern half of the Earth.
On 17 July, a piece about/for four kilometers wide enters the Earth’s atmosphere with a massive explosion.
About half of the piece is destroyed, but the remaining part hits the South Atlantic at 200 times the speed of sound. The sea boils and a huge hole is made in the seabed. Huge waves are created and spread outwards from the hole. The wall of water, a kilometer high, rushes towards southern Africa at 800 kilometers an hour. Cities on the African coast are totally destroyed and millions of people are drowned.
Before the waves reach South America, the second piece of the comet lands in Argentina.
Earthquakes and volcanoes are set off in the Andes Mountains. The shock waves move north into California and all around the Pacific Ocean. The cities of Los Angeles, San Francisco and Tokyo are completely destroyed by earthquakes. Millions of people in the southern half of the earth are already dead, but the north won’t escape for long. Because of the explosions, the sun is hidden by clouds of dust, and temperature around the world falls to almost zero. Crops are ruined. The sun won’t be seen again for many years. Wars break out as countries fight for food. A year later, no more than 10 million remain alive.
Could it really happen In fact, it has already happened more than once in the history of the Earth. The dinosaurs (恐龙) were on the Earth for over 160 million years. Then 65 million years ago they suddenly disappeared. Many scientists believe that the Earth was hit by a piece of object in space. The dinosaurs couldn’t live through the cold climate that followed and they died out. Will we meet the same end
Reasons Results
One piece hits the South Atlantic at 200 times
faster than the speed of sound.
The sea (46) and a huge hole is made in the seabed. A tsunami(海啸) hits southern Africa, (47) cities on the African
coast, and (48) millions of people.
A (49) (50) happens when the four-kilo-
meter-wide piece of comet enters the
Earth’s (51)
The sun is (52) . by clouds of dust and the temperature falls to
almost zero, (53) crops. Wars break out for food and only 10
million people remain. The human beings are (54) the danger of (55) out.

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