1 . If the ________ are just right, some of the electrons inside a(n) ________ will arrange themselves into a tidy honeycomb pattern（蜂巢状结构）— like a solid within a ________. Physicists have now ________ imaged these ‘Wigner crystals’, named after the Hungarian-born ________ Eugene Wigner, who first imagined them almost 90 years ago. Researchers had ________ created Wigner crystals and measured their properties before, but this is the first time that anyone has actually taken a snapshot of the patterns, says study co-author Feng Wang, a physicist at the University of California, Berkeley. “If you say you have an electron crystal, show me the crystal,” he says. The results were published on 29 September in Nature.

To create the Wigner crystals, Wang’s team built a device ________ atom-thin layers of two similar semiconductors: tungsten disulfide（二硫化物）and tungsten diselenide（联硒化物）. The team then used an electric field to tune the density of the electrons that moved freely along the interface between the two layers.

In ordinary materials, electrons zoom around too quickly to be ________ affected by the ________ between their negative charges. But Wigner predicted that if electrons travelled slowly enough, that repulsion would begin to dominate their behaviour. The electrons would then find ________ that minimize their total energy, such as a ________. So Wang and his colleagues slowed the electrons in their device by ________ it to a few degrees above absolute zero.

A mismatch ________ the two layers in the device also helped the electrons to form Wigner crystals. The atoms in each of the two semiconductor layers are slightly different distances apart, so pairing them together creates a honeycomb ‘moiré pattern’（蝶纹结构）, similar to that seen when overlaying two grids. That repeating pattern created regions of slightly lower energy, which helped the electrons ________. The team used scanning tunnelling microscope(STM) to see this Wigner crystal. In an STM, a metal tip hovers above the surface of a sample, and a(n) ________ causes electrons to jump down from the tip, creating an electric current.

1.

A．conditions

B．situations

C．environments

D．circumstances

2.

A．item

B．thing

C．material

D．article

3.

A．cube

B．solid

C．structure

D．dimension

4.

A．occasionally

B．surprisingly

C．indirectly

D．directly

5.

A．scientist

B．theorist

C．predictr

D．fantasist

6.

A．potently

B．absolutely

C．definitely

D．convincingly

7.

A．observing

B．containing

C．watching

D．undertaking

8.

A．significantly

B．obviously

C．tiny

D．inconspicuously

9.

A．magnetic field

B．force

C．attraction

D．repulsion

10.

A．interrelations

B．arrangements

C．requirements

D．pairs

11.

A．sphere pattern

B．cylinder pattern

C．honeycomb pattern

D．corn pattern

12.

A．heating

B．cooling

C．speeding

D．slowing

13.

A．within

B．between

C．among

D．through

14.

A．speed up

B．stop

C．settle down

D．calm down

15.

A．light

B．voltage

C．energy

D．ion

2 . Revealing the source of Jupiter’s x-ray auroral flares

Abstract

Jupiter’s rapidly rotating, strong magnetic field provides a natural laboratory that is key to understanding the dynamics (动力学) of high-energy plasmas (等离子体). Spectacular auroral (极光的) X-ray flares (耀斑) are diagnostic of the most energetic processes governing magnetospheres but seemingly unique to Jupiter. Since their discovery 40 years ago, the processes that produce Jupiter’s X-ray flares have remained unknown. Here, we report simultaneous (同时的) in situ satellite and space-based telescope observations that reveal the processes that produce Jupiter’s X-ray flares, showing surprising similarities to terrestrial ion aurora. Planetary-scale electromagnetic waves are observed to modulate (调节) electromagnetic ion cyclotron waves, periodically causing heavy ions to precipitate and produce Jupiter’s X-ray pulses. Our findings show that ion aurorae share common mechanisms across planetary systems, despite temporal, spatial, and energetic scales varying by orders of magnitude.

INTRODUCTION

Aurorae, observed from planetary polar regions across the solar system, are displays of light that are produced when energetic particles precipitate along magnetic field lines and transfer their energy to the atmosphere. Jupiter’s soft x-ray aurorae are produced by energetic [~ (MeV) (电子伏)] heavy ions (S and O), originally from the moon Io’s (木卫一的) volcanic activities. The dynamic X-ray emissions often pulse with a regular beat of a few tens of minutes. The spectacular quasi-periodic (准周期性的) auroral pulsations at Jupiter have also been observed in ultraviolet (UV), infrared, and radio emissions. The X-ray aurorae are predominately confined (主要局限于) to the region poleward of Jupiter’s main aurora, connecting to Jupiter’s outer magnetosphere via magnetic field lines. The mapping of the emissions leads to the suggestion that the particle precipitations were driven by magnetic reconnection. However, observations show that the x-ray pulsations last for several Jupiter days or longer, evidencing that the driver may not be a transient process like magnetic reconnection.

To date, 40 years after their discovery, the mechanisms that cause these X-ray aurorae remain unknown. Simultaneous measurements of the magnetospheric environment and the auroral emissions are critical to revealing their driving mechanisms. Here, we present observations of Jupiter’s unique x-ray aurorae with simultaneous in situ measurements from the magnetosphere. In this study, we reveal the physical driver for Jupiter’s pulsating x-ray emissions by analyzing simultaneous in situ measurements from Juno and remote spectroscopic imaging by XMM-Newton telescope (XMM，牛顿卫星) during 16 and 17 July 2017. XMM’s European Photon Imaging Camera (EPIC-pn and MOS) instruments provided spatial, spectral, and timing data of Jupiter for a continuous 26-hour (~2.6 Jupiter rotations) observation from 18:26 UT on 16 July to 22:13 UT on 17 July, which was shifted to account for the ~46-min light travel time between Jupiter and Earth. This XMM observation was planned to coincide with the time when NASA’s Juno spacecraft was moving from 62 to 68 RJ (1 RJ = 71 492 km) radially away from the planet in the Southern Hemisphere in the predawn sector between ~0400 and 0430 magnetospheric local time (MLT).

Ionosphere-magnetosphere (电离层) mapping from previous observations suggested that the origins of Jupiter’s X-ray auroral pulsations occurred at these distances from the planet. Juno provided contemporaneous (同时发生的) in situ measurements from the plasma sheet only when Jupiter’s north magnetic pole tilted to Earth. Therefore, we focus on the northern aurora, for which Juno’s in situ measurements detail what was happening in the plasma sheet during the X-ray pulses. At Jupiter, the analysis of these comparisons between in situ and remote sensing observations is more complex than at Earth. At Earth, during the time scale of an auroral event, typically tens of minutes, a spacecraft in the terrestrial magnetosphere usually travels little (e.g., hundreds of kilometers) in comparison to the spatial scale of a magnetospheric event (e.g., several Earth radii) that would cause a large auroral brightening so that this in situ spacecraft could be magnetically connected to the aurora region over the full auroral lifetime. This is not true for Jupiter, because the footprint of the aurora (which is rotating with Jupiter) with respect to Juno’s location changes substantially during an observation. There are also substantial travel times (a few tens of minutes) along the magnetic field expected from the outer magnetosphere to the Jovian aurora. Therefore, the correlation between a single outer magnetosphere event in Jupiter’s in situ measurements and a single auroral pulse cannot be expected on a one-to-one level basis. Instead, a series of successive events are required to draw reliable careful correlations, with the regular periodicity of the x-ray flares, providing an invaluable diagnostic signature of the source process.

(Adapted from an essay on Science.)

1. What does the essay focus on?

A．The X-ray pulses happening on Jupiter.

B．The formation of the aurora in the pole of Jupiter.

C．The ways to teach people how to appreciate auroras.

D．The process of detecting the X-ray pulses on Jupiter.

2. What will the author present in the next content of the essay?

A．Their conclusions.	B．Their measure to do the research.
C．Discussion of some problems of preciseness.	D．Their acknowledgements.

3. The word “infrared” is underlined and in Italics. What is the meaning of the word?

A．辐射

B．红外线技术的

C．太阳风

D．红外线

4. Which of the followings is NOT TRUE about the auroral flares on Jupiter?

A．The strong magnetic is a good breakthrough point to research the auroral flares.

B．The X-ray pulses will last for several days on Jupiter.

C．The soft X-rays are caused by high-energy ions.

D．The X-ray pulses beat regular on Jupiter.

3 . How to Feel Connected

It's easy to feel disconnected from what is going on around you in today's fast-paced world.     1     You can get in touch and feel connected, however, by following the tips below:

Consider why you feel disconnected. Knowing what is making you feel disconnected can help you choose the best ways to address it.     2     Ask yourself these questions: Are you keeping yourself occupied with work too much? Do you rely on electronic communication instead of face to face communication? Do you lack friendships that are satisfying?

Interact with people in person. Technology is a great way to stay in touch, but sometimes you need to spend time with other people in person.     3     You can also take steps to feel more connected by making small-talk with strangers who are sharing parts of your day.

    4    

Your loved ones could feel shy, so you may never know how to improve your relationship unless you ask the right questions. Asking them to open the doors can give you some insight on what you can do. Learning this information can help to strengthen your bond.

Show your commitment to them. Simply showing up and being there for your loved ones says a lot about how much you value your relationships. Putting in the time shows them that you are committed and want to stay connected.     5    

Show appreciation. A simple “thank you” goes a very long way. Unfortunately, it is something that people who are close often take for granted. Telling someone you appreciate their time, love, and efforts can strengthen your bond and help you to become more connected.

A．Ask others what they need from you.

B．Sometimes you can feel isolated and distant from the ones you love.

C．Be brave to express your love.

D．Reach out to people to schedule a time to get together.

E．Attending family events, or simply visiting someone once a week can help to strengthen your relationship and keep it strong.

F．Targeting your efforts toward those issues allows you to close that distance more effectively.

G．You can have a gift delivered to friends on special occasions.

4 . 假如你是高二1班学生李华，学校校报征集题为“你心中的成功人士”的稿件，请你根据以下表格所提示内容介绍“人民英雄”张定宇的事迹。向校报投稿。

A successful person in my mind

基本信息	武汉市金银潭医院院长。 1963年12月出生于河南
主要事迹和所做贡献	1986年毕业于同济医科大学，成为一名医生； 1997-1999年参加中国援助阿尔及利亚医疗队（Algeria）； 2016年成为武汉金银潭医院院长； 2018年被诊断为渐冻症（be diagnosed with ALS）；仍然全身心地投入工作，帮助新冠患者得到及时救治； 2020年在疫情防控工作中做出突出贡献。
对他的评价和 荣誉称号	一个斗士 2020年8月被授予“人民英雄”国家荣誉称号
从他身上，你对成功的理解	……

参考词汇：
同济医科大学：Tongji Medical College 武汉金银潭医院：Wuhan Jinyintan Hospital
院长：president /head                           人民英雄：the People’s Hero                  
__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

5 . The fact that members of one culture do not express their emotions as openly as do _______ of another does not mean that they do not experience emotions.

A．it

B．one

C．that

D．those

6 . 阅读下面材料，根据其内容和所给段落开头语续写两段，使之构成一篇完整的短文。

The Principal and the Popcorn Popper

Spring was approaching. Principal （校长）Peters was wandering in the empty part of the huge school yard when the students^' request flashed through his mind again. It couldn't be better to eat the cabbages, carrots, or eggplants planted by themselves. But how to raise money for seeds and tools?

The topic came up at the teachers' meeting. Teachers suggested various means of collecting money with enthusiasm； one teacher suggested, “We have a popcorn popper （爆米 花机）in the teachers' lounge （休息室）.How about kids making popcorn to sell?”

When the popcorn proposal reached the students, they jumped with joy. Agreement was reached -every Thursday, in their labor course, by selling popcorn for 25 cents a bag, they could enjoy a snack while raising money to buy seeds and tools for their garden.

Soon the first Thursday came. Principal Peters got to his office as usual just right next to the teachers' lounge. Hearing popping sound, he smiled, for it meant the promise of the potential garden. But it was REALLY loud. He wrapped a scarf around his head to block his ears. When the first Thursday was over, he breathed a sigh of relief. But the next Thursday, popping sound happened again. This time, he had brought earplugs. The day, it seemed, would last forever. But for the kids' garden dream, he put up with it willingly.

The following Thursdays witnessed Principal Peters attempting to pile gym mats against his office walls and asking the fifth grade to practice for their concert in the hallway outside his office. The "unbearable" popping sound seemed to have taken root in his head! But for the kids' vegetable garden dream, he put up with it willingly.

On the 11th Thursday, he went to the teachers' lounge again to see how much money was still needed. Seeing the Principal coming with a hard-hidden painful expression, the students responded cheerfully, “Only with 41 dollars our garden dream will come true.” Hearing this, Principal Peters left without saying anything.

注意:1.续写词数应为150左右；
2.请按如下格式在答题卡的相应位置作答。

Shortly afterward, Principal Peters came back with 41 dollars.

_______________________________________________________________________________________________________________________________________________________________________________

“POPCORN", the cute students answered the Principal's question jokingly.

_______________________________________________________________________________________________________________________________________________________________________________

7 . Without gravity（重力), we ________ walk on the ground as freely as we do now.

A．couldn't

B．mustn't

C．shan't

D．needn't