晶体是由原子或分子在空间()、()排列所构成的固体物质。

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问题:

晶体是由原子或分子在空间()、()排列所构成的固体物质。

考点:材料科学基础材料科学基础题库
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X、Y、Z、W均为短周期元素,它们在元素周期表中的位置如图所示。若Y原子的最外层电子数是次外层电子数的3倍,下列说法中正确的是 (   )

A.原子半径:W> Z>Y>X

B.最高价氧化物对应水化物的酸性:Z>W>X

C.4种元素的单质中,Z单质的熔、沸点最低

D.W单质能与水反应,生成一种具有漂白性的物质

题型:填空题

In its plans to develop Greece as a year-round tourist destination, the Ministry of Tourism is focusing on alternative forms of tourism, beyond the sun, sea and sand classical summer holiday. Among other sectors, these include health and beauty tourism. Apart from stunning natural beauties, nature has endowed Greece with hot springs whose therapeutic properties were already known in ancient times. Hippocrates, the father of medicine, was the first to discover their virtues some 25 centuries ago. The geographical location of these springs is not accidental as it is related either to tectonic events or volcanic activities. Their waters are therapeutic for ailments such as rheumatism, arthritis and complaints related to lungs, kidneys, blood circulation and dermatology, among others. Of more than 750 natural springs, around 80 operate professionally as natural spas, many with accommodation and other facilities. In consultations with tourism associations, hoteliers and tourism investment consultants, the government is drafting a new law to define the rules for health tourism. Expected to be approved by Parliament early next year, the law will establish the legal framework and the prerequisites for health tourism centers, including provisions for handicapped guests. One condition will be that such centers will have to operate all year, not just in summer. Another is that hotels providing health facilities should be near a hospital or an airport. The Development Law, which came into force in December 2004, provides attractive incentives, such as subsidies or tax breaks for health tourism center investments. The government is encouraging regional development in areas in northwestern Greece. Doctors and investors from Sweden, Britain and Germany have already shown interest in establishing health tourism centers in Greece, to take advantage of the country’s mild climate, low humidity and year-round sunshine. In addition to hydrotherapy, some centers will deal with illnesses of the psyche — depression, psychological problems and addictions. The serenity of many parts of Greece’s countryside is seen as therapeutic for people from northern countries where cold, dreary climates can lead sufferers to depression and suicide. Spread throughout Greece, many natural mineral springs are owned by the National Tourism Organization of Greece and managed by the Tourism Development Co. The latter is gradually divesting itself of its. large and diverse portfolio through long-term leasing of its holdings, including mineral springs and spas.

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JIT生产技术的要点有哪些?

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患儿,男性,出生后7个月,因腰骶部皮下包块就诊。检查:腰骶部外突型肿块,大小4cm×3cm,肿块表面有稀疏的长毛及色素沉着,有囊性感,透光试验阳性。根据以上情况,最可能的诊断是()

A.神经根囊肿

B.畸胎瘤

C.脂肪瘤

D.脊膜膨出

E.神经纤维瘤

题型:填空题

二尖瓣结构不包括()

A.瓣环

B.瓣叶

C.腱索

D. * * 肌

E.室间隔膜部

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