中东地区刚考完，来回报CD

zizihuang

狗主一二站没上600，三战680，真的是想欢呼！虽然没有上700但是已经从自我怀疑跳脱出来了！谢谢CD里各位提供寂静和各位整理寂静的大侠们！！！！！尤其是整理阅读的那位

作文考了那片要taxpayers fund 在 convention 旁建luxury hotel 来吸引visitor的

DS: |X| + X/2<4 1: X>-12
2: X<-6
这题，我真的不记得自己选的啥

还有一篇关于地质的一个M开头的名字在1930年代提出了一个理论，提出了关于ice age 什么的。 然后1940年有些人发现了新的证据推翻了他，说什么glacier till 不会像M说的那样，后来又有新发现，说它的理论还是值得研究。。。这篇很长。。。后来时间不够没怎么看懂。
阅读考了羊毛的那篇，其中一题问了在人们公元4000年前，如果人们没有取用羊毛，骨头会怎么样。确认选骨头里老的男性羊少
还有一篇美国从debtor creditor。文章还算简单。就是讲了两派人的观点，观点一是说这个说明美国经济在发展，，因为如果真的是美国经济繁荣的话，外国资本他们应该有ownership 在里面，大概是这个意思，但是，现在却都是只是portfolio之类另一个说证明美国经济变不好。提到了两个关键词的作用，我选了，为了提出第二个观点的提出。
还有两篇一篇是关于Pluto的密度的，第一段就是说随着时间发展，人们先观察到了Pluto上的表面都是frozen的methane，然后根据一般的规律离太阳越远的星期密度越低，结果居然发现Pluto的密度比水重了两倍。然后第二段作者进行原因的推测，说本来是Pluto都是冰，有段时间突然热了然后石头就进到core里面去了，外面覆盖了一层冰的methane. 这里有个推论题，答案是Pluto表面的Frozen methane 是在人们发现rock core之前发现的。
有时间的看看下面这段

Spectroscopic （这个词那篇文章里有）analysis has revealed the existence of frozen nitrogen, methane, and carbon monoxide on the surface of Pluto. Such ices have a tendency to vaporize, producing an atmosphere. Since the proportion of any gas in such an atmosphere depends directly on how readily the corresponding ice vaporizes, astronomers have concluded that the components of Pluto's atmosphere are nitrogen, carbon monoxide, and methane, in order of decreasing abundance.

关于星星Spin的我也找了一些资料，希望后面备考的同学能用上

A neutron star with a cosmic case of indigestion could help to explain why some of these ultra-dense stellar embers spin much more quickly than others.

Astronomers have found that the gluttonous star stole material from a companion star before blasting it away again – apparently confirming their ideas about how such rapidly-spinning pulsars might develop.

Neutron stars are the remains of massive stars that have exploded, leaving only city-sized balls of neutrons. They often emit intense beams of radio waves from their poles, which are detected as a signal that “pulses” as the star spins. The stars are then known as pulsars.

Ordinary pulsars spin just a few times per second, but some spin hundreds of times faster. Astronomers suspect that many of these “millisecond pulsars” are essentially no different from ordinary pulsars, except that their rotation has sped up as they have stripped material from nearby stars.

Stolen girdle

The stripped material accretes into a disc around the neutron star, transferring angular momentum to the star – which makes it rotate more quickly – and shorting out its production of radio waves. Eventually, however, the intense magnetic fields around the star blast the accreted material away and the neutron star once again becomes detectable as a pulsar, spinning much more quickly than before.

Until recently, however, there was no direct evidence for this process. Now Anne Archibald of McGill University in Montreal and colleagues say they’ve identified a millisecond pulsar that was once surrounded by an accretion disc of material from its companion star.

The neutron star, part of a pair of stellar objects called J1023, sits in the Milky Way some 4000 light years from Earth and spins 592 times per second. It was discovered in 2007 in a survey of the sky conducted with the Green Bank Telescope in West Virginia. Its companion is a star with about half the mass of the sun; the two objects orbit each other roughly every five hours.

Archibald’s team looked back through archived data from other telescopes. They found that, in 2000, the neutron star was encircled by a disc of material stolen from its companion. The intense gravity of the pulsar made this disc dense and hot, glowing four times more brightly than the companion star.

However, by 2002 the disc had disappeared, presumably cast out by the intense magnetic fields around the star. Now the neutron star looks like a pulsar again, beaming intense radio waves from its poles.

Terminal pulsar

This is the first time a fast-spinning pulsar has been shown to have gathered matter from another star. But the process is probably coming to an end in J1023’s case: the neutron star is now spinning so fast that any matter torn off the companion star in the future might simply be flung out of the system altogether.

“What we found is a system that’s right on the end, that’s turning from an accreting system into a millisecond pulsar,” Archibald says.

“It’s another piece in the puzzle of how you get from a neutron star to essentially the fastest rotating objects in the universe,” says Deepto Chakrabarty of MIT. “The fact that this object is apparently making the transition from one state to the other could be a big step forward.”

Nonetheless, astronomers are hoping the J1023 pulsar will grab more material from its companion soon. That would be detectable as a shorting-out of radio waves around the star. The team has already enlisted the help of amateur astronomers to look out for another accretion event.

还有那篇 wasp 保护树的我也找了一些文背景文章

When hornworm caterpillars eat tobacco plants, they doom themselves with their own spit. As they chew away, a chemical in their saliva reacts with airborne substances that are released by the beleaguered plants. This chemical reaction sends out a distress signal that is heard and answered by the predatory big-eyed bug. The bug eats hornworm caterpillars. Drawn by the chemical SOS of plants under distress, it finds plenty to devour.

Many plants release airborne chemicals to defend themselves against very hungry caterpillars. These “plant volatiles” spread far and wide, summoning reinforcements to the plant’s defence. Some attract predators like the big-eyed bug; others call upon parasitic wasps that lay their eggs inside the caterpillars, which are soon devoured from the inside out.

Silke Allmann and Ian Baldwin from the Max Planck Institute studied a particular group of SOS chemicals called ‘green leaf volatiles’ (or GLVs), which are released almost immediately from wounded leaves. They come in two slightly different forms known as Z and E. When the duo injured tobacco leaves themselves, they released far more of the Z versions than the E ones. By contrast, leaves that were attacked by hornworms released both Z and E forms in equal amounts.

Allmann and Baldwin showed that something in the hornworm spit was causing this change. If they applied the saliva to a wound, without any caterpillar, the plant gave off the same balanced aroma of Z and E chemicals. For the moment, no one knows which of the many compounds in the caterpillar’s saliva prompts this change, but whatever the mystery chemical is, it directly converts the Z form into the E one. You can see the reaction taking place in a test tube, but only when the saliva of a hornworm is added. Extracts made from tobacco leaves won’t do the trick.

When Allmann and Baldwin tested the spit of other pests that eat tobacco leaves – the army beetworm and cotton leafworm – the leaves’ emissions were still Z-heavy.  This means that the release of Z and E volatiles in equal numbers sends out a very particular message: it says that the plant is being specifically attacked by hornworms, rather than any other type of caterpillar.

And the big-eyed bug is listening. Allmann and Baldwin tested the bug’s preferences by gluing hornworm eggs to tobacco plants and dabbing artificially prepared mixtures of Z and E volatiles. They found that the predator devoured more eggs when it caught a whiff of Z and E in equal measure, over a bouquet that smelled predominantly of Z. So by the very act of eating its favourite plant, the tobacco hornworm creates a chemical reaction that summons one of its predators.

This is a brilliant defence on the part of the plant but it seems baffling that the hornworm should produce a chemical in its spit that ultimately increases its risk of being eaten. It’s a mystery, but Allmann and Baldwin think that the caterpillars might benefit from the E volatiles, possibly because they protect it against infections. If that’s the case, the risk of summoning a marauding big-eyed bug might be worth the price of a meal and defence against disease.

鱼丸要考700

mark，谢谢

yichenny

中东  wowww 好酷