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问题 填空题

（1）用化学用语表示下列物质或粒子：

4个五氧化二磷分子______；6个硝酸根离子______；纯碱______．

（2）写出下列符号中“2”的意义：

O2______；Fe2+______．

（3）硫酸铁中硫元素的化合价为______．

答案

（1）根据分子的表示方法：正确书写物质的化学式，表示多个该分子，就在其化学式前加上相应的数字，因此4个五氧化二磷分子表示为：4P2O5； 根据离子的表示方法：在表示该离子的元素符号右上角，标出该离子所带的正负电荷数，数字在前，正负符号在后，带1个电荷时，1要省略．若表示多个该离子，就在其元素符号前加上相应的数字；因此6个硝酸根离子表示为：6NO3-；

纯碱即碳酸钠，由-2价的碳酸根和+1价的钠元素构成，根据化合物化学式的书写步骤，纯碱的化学式为：Na2CO3；

故答案为：4P2O5；6NO3-；Na2CO3；

（2）根据标在元素符号右下角的数字表示一个分子中所含原子的个数；因此O2中“2”的意义表示：一个氧分子中含有2个氧原子；

根据标在元素符号右上角的数字表示离子所带电荷数；因此Fe2+中“2”的意义表示：一个亚铁离子带2个单位的正电荷；

故答案为：一个氧分子中含有2个氧原子；一个亚铁离子带2个单位的正电荷；

（3）根据元素化合价的表示方法：确定出化合物中所要标出的元素的化合价，然后在其化学式该元素的上方用正

负号和数字表示，正负号在前，数字在后，硫酸铁中硫元素的化合价为+6价，表示为：Fe2（

+6
S
O4）3；

故答案为：Fe2（

+6
S
O4）3．

综合

(10分）【旅游地理】

家住海南的小王随某旅行团到某地旅游，下表是该旅行社行程安排表。

（1）小王在这次旅游过程中游览的旅游景点主要是哪类旅游资源？（4分）

（2）结合所学知识简述小王旅游前和旅游过程中应注意的问题。(6分）
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单项选择题


Directions: There are four passages in this part. Each of the passage is followed by five questions or unfinished statements. For each of them there are four choices marked A, B, C and D. Choose the best one and mark your answer on the ANSWER SHEET with a single line through the center.
Passage One

When TV news programs report wars or disasters, the editors rarely use the most horrifying pictures of dead or wounded victims because they don’t want to upset their viewers. Even so, viewers are usually warned in advance that they "may find some of these scenes disturbing", so they can look away if they choose. But the men and women whose job is to record those scenes — the TV cameramen — have no such choice. It is their duty to witness the horrors of the world and record them no matter how gruesome and unpleasant they may be. Consequently, it is one of the most dangerous, exposed and emotionally taxing jobs the world has to offer.
Today, the demand for their work is rising, the explosion of satellite broadcasting and 24hour news in recent years has created an almost insatiable demand for TV information. But major broadcasters and TV news agencies — such as Reuters and WTN — have never had enough staff to meet the worldwide demand for up-to-date pictures, so increasingly they turn to "freelance" TV cameramen.
These freelance cameramen are independent operators tied to no particular organization. They will work for any company which hires them, be it for just a few hours or for several weeks in a war zone. But if the freelance cameraman is injured, in the course of the job, the TV company is not responsible for him. The freelancer must survive on his own.
"TV will always need hard, vivid moving pictures which are fresh, but these companies feel uncomfortable with large numbers of employees on their books," explains Nick Gowing, once foreign editor for Britain’s Channel 4 news and now a BBC presenter.
"By hiring freelancers, they can buy in the skills they need only when they need them. It also enables them to contract out the risk," he says.

According to the passage, the freelance cameramen ______.

A．are tied to many TV news agencies

B．have better skills than other cameramen

C．have to take tremendous risks in the course of work

D．need to contract our risks of work for TV companies
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