如何防止氯气中毒？

对途经港、澳或第三国（地区）中转的美国、日本、韩国、欧盟输华货物木质包装如无相应包装证书或声明的，应抽样查验。（）

切勿触摸（），很多烧伤和表皮伤害都是由电台发射造成的。

A、电台电瓶线

B、电台散热器

C、电台发射天线

D、电台话筒线

从某批产品中，有放回地抽取产品二次，每次随机抽取1件。假设事件A：“取出的2件产品中至多有1件是二等品”的概率P（A）=0.96，

（Ⅰ）求从该批产品中任取1件是二等品的概率p；

（Ⅱ）若该批产品共100件，从中任意抽取2件，ξ表示取出的2件产品中二等品的件数，求ξ的分布列。

Soccer is played by millions of people all over the world, but there have only been few players who were truly great. How did these players get that way---was it through training and practice, or are great players “born, not made”? First, these players came from places that have had famous stars in the past---players that a young boy can look up to and try to imitate(模仿). In the history of soccer, only seven countries have ever won the World Cup---three from South America and four from western Europe. There has never been a great national team---or a really great player---from North America or from Asia. Second, these players have all had years of practice in the game. Alfredo Di Stefano was the son of a soccer player, as was Pele. Most players begin playing the game at the age of three or four.

Finally, many great players come from the same kind of neighbourhood---a poor, crowded area where a boy’s dream is not to be a doctor, lawyer, or businessman, but to become a rich, famous athlete or entertainer(艺人). For example, Liverpool, which produced the Beatles, had one of the best English soccer teams in recent years. Pele practiced in the street with a “ball” made of rags(破布). And George Best learned the tricks that made him famous by bouncing the ball off a wall(对着墙壁踢球) in the slums(贫民窟) of Belfast.

All great players have a lot in common, but that doesn’t explain why they are great. Hundreds of boys played in those Brazilian streets, but only one became Pele. The greatest players are born with some unique quality that sets them apart from all the others.

46. According to the writer, which of the following statements is true?

A. Soccer is popular all over the world, but truly great players are few.

B. Millions of people all over the world are playing soccer, but only seven countries have ever had famous stars.

C. Soccer is played by millions of people all over the world, but only seven countries from South America and western Europe have ever had great national teams.

D. Soccer is one of the most popular games all over the world, but it seems the least popular in North America and Asia.

47. The world “tricks” at the end of Paragraph 2 is closest in meaning to ______.

A. experience      B. cheating         C. skills          D. training

48. The Brazilian streets are mentioned to illustrate that ______.

A. famous soccer players live in slum areas

B. people in poor areas are born with some unique quality

C. children in poor areas start playing football at the age of three or four

D. a great soccer player may be born in a slum area

49. In the last paragraph the statement “…but only one became Pele” indicates that ______.

A. Pele is the greatest soccer player

B. the greatest players are born with some unique quality

C. Pele’s birthplace sets him apart from all the others

D. the success of a soccer player has everything to do with the family background

50. The writer mentions all the factors that may affect a soccer player’s success except ______.

A. his family background               B. his neighbourhood

C. his practice                              D. his character

低压用户接户线自电网电杆至用户第一个支持物最大允许档距为（）。

A.25m；

B.50m；

C.65m；

D.80m。