问题 填空题

有A、B、C、D四种元素,已知A是地壳中含量第二多的非金属元素,B元素原子失去电子后只剩一个质子,C元素的单质可使带火星的木条复燃,D元素的原子核外有三个电子层,最外层电子数是第一层电子数的3倍。请回答:

(1)A元素的名称           ;(2)B元素组成单质的符号                  

(3)n个D离子             ;(4)C、D元素组成的化合物的化学式         

答案

(1)硅元素 ;

(2)H2

(3)n S2-

(4)SO2或SO3

题目分析:地壳中含量第二多的非金属元素是硅元素,失去电子后只剩一个质子的是氢元素,其组成的单质为氢气,符号为H2,可使带火星的木条复燃的单质是氧气,故C元素为氧元素,原子核外有三个电子层,最外层电子数是第一层电子数的3倍的是硫元素,其核外电子排布为第一层2个,第二层8个,第三层6个,故D为硫元素。n个D离子写成n S2-; C为氧元素,D为硫元素,它们组成的化合物的化学式SO2或SO3

单项选择题
阅读理解

Friendships between Americans can be close and real, yet disappear soon if situations change. Neither side feels hurt by this. Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while — then no more. If the same two people meet again by chance, even years later, they pick up the friendship. This can be quite difficult for us Chinese to understand, because friendships between us flower more slowly but then may become lifelong feelings, extending (延伸) sometimes deeply into both families.

Americans are ready to receive us foreigners at their homes, share their holidays, and their home life. They will enjoy welcoming us and be pleased if we accept their hospitality (好客) easily.

Another difficult point for us Chinese to understand Americans is that although they include us warmly in their personal everyday lives, they don’t show their politeness to us if it requires a great deal of time. This is usually the opposite of the practice in our country where we may be generous with our time. Sometimes, we, as hosts, will appear at airports even in the middle of the night to meet a friend. We may take days off to act as guides to our foreign friends. The Americans, however, express their welcome usually at homes, but truly can not manage the time to do a great deal with a visitor outside their daily routine. They will probably expect us to get ourselves from the airport to our own hotel by bus. And they expect that we will phone them from there. Once we arrive at their homes, the welcome will be full, warm and real. We will find ourselves treated hospitably(好客).

For the Americans, it is often considered more friendly to invite a friend to their homes than to go to restaurants, except for business matters. So accept their hospitality at home!

小题1:The writer of this passage must be ______.

A.an American

B.a Chinese

C.a professor

D.a student小题2: Which of the following statements is TRUE according to the passage?

A.Friendships between Americans usually extend deeply into their families.

B.Friendships between Americans usually last for all their lives.

C.Americans always show their warmth even if they are very busy.

D.Americans will continue their friendships again even after a long break.小题3: From the last two paragraphs we can learn that when we arrive in America to visit an American friend, we will probably be ______.

A.warmly welcomed at the airport

B.offered a ride to his home

C.treated hospitably at his home

D.treated to dinner in a restaurant小题4: The underlined words “generous with our time” in Paragraph 3 probably mean ______.

A.strict with time

B.serious with time

C.careful with time

D.willing to spend time小题5: A suitable title for this passage would probably be “______”.

A.Friendships between Chinese

B.Friendships between Americans

C.Americans’ hospitality

D.Americans’ and Chinese’s views of friendships