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问题 填空题

火柴头上主要含有氯酸钾、二氧化锰、硫磺、玻璃粉；火柴盒两边的摩擦层是由红磷和玻璃粉调和而成的．火柴着火的主要过程是：①火柴头在火柴盒上划动时产生的热量使磷燃烧；②磷燃烧放出的热量使氯酸钾分解；③氯酸钾分解产生的氧气与硫反应，放出的热量使火柴梗着火．请写出以上①②③中反应的化学反应式（或化学方程式）．

①______

②______

③______

答案

①磷与氧气在点燃条件下反应生成五氧化二磷．

该反应的化学方程式为：4P+5O2

 点燃 
.
 
2P2O5．

②氯酸钾在二氧化锰的催化作用和加热条件下反应生成氯化钾和氧气．

该反应的化学方程式为：2KClO3

 MnO2 
.
 
△
2KCl+3O2↑．

③硫与氧气在点燃条件下反应生成二氧化硫．

该反应的化学方程式为：S+O2

 点燃 
.
 
SO2．

故答案为：

①4P+5O2

 点燃 
.
 
2P2O5；

②2KClO3

 MnO2 
.
 
△
2KCl+3O2↑；

③S+O2

 点燃 
.
 
SO2．

实验题

请回答下列实验中制取气体的有关问题。

(1)下图是用KMnO4与浓盐酸反应制取适量氯气的简易装置。 装置B、C、D的作用分别是：

B_______ ; C __________; D__________ ;

(2)在实验室欲制取适量NO气体。

①下图中最适合完成该实验的简易装置是 _________（填序号）;

②根据所选的装置完成下表（不需要的可不填）：

③简单描述应观察到的实验现象____________。

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单项选择题

第2篇 Tightened Visa Regulations


According to South Korea’s new visa regulations, native speakers of English who intend to teach English in South Korea will be required to undergo criminal record checks, medical and drug tests, provide sealed academic transcripts and have their university diplomas inspected, The Korea Times has reported. The tightened regulations will affect an estimated 17,000 foreigners that hold E-2 visas specifically for foreign language teachers.
The most controversial requirement is that English teachers residing outside South Korea will have to have an interview at a South Korean embassy before taking up their teaching posts. For applicants living in remote areas in Canada, Australia or the US, this is an additional travel burden. Meanwhile, foreign teachers currently living in South Korea must leave the country after their one-year contracts end and renew their visas at a South Korean embassy in their home country or third country. Before the changes, they could renew their visas by visiting a neighboring country and return without additional documentation.
The visa changes are a reaction to public concern about the suitability of some foreign teachers. A report from the South Korean Ministry of Education and Human Resources Development shows between 2001 and August of this year, 1,481 foreign language teachers have been caught for a range of offenses including forged degrees, visa violations and general lawbreaking.
But the changes are likely to slow up the supply of teachers to South Korea’s English language education sector. According to Michael Dully, manager of a teacher placement service in South Korea, applicants have to spend a few hundred dollars and several months on getting affidavits for documents. "South Korea has put up too many hoops to jump through. " he said, adding that foreigners would seek work elsewhere. Most foreigners wonder if the experience of working in South Korea will be worth the burden of the paper work and increasing restrictions. "I don’t think (South) Korea has thought this through. " said Scott McInnis, a Canadian teacher based in Incheon near Seoul. "This is a reactionary move by the government that will have p implications for the EFL community. "
As part of efforts to ease the discontent, the South Korean Ministry of Justice has granted a three-month grace period for current E-2 visa holders to prepare the necessary documents.

The new visa policy aims at ______.

A．limiting too many foreigners entering into South Korean to teach English

B．improving foreign language teaching in South Korea

C．easing the discontent of the South Korean people to the government

D．slowing up the supply of English teachers to South Korea
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