确诊流脑的依据是 A．流行季节 B．突然发病、高热、头痛、呕吐 C．脑膜刺激征阳性

为了创建平安校园，学校开展了交通安全知识和禁毒知识等方面的宣传教育活动。文化、工商等部门对学校周围的网吧、小卖部进行了清理整顿。父母也叮嘱孩子注意交通安全，学会防范意外伤害，保护自己。

（1）上述材料体现了对未成年人的那些保护？

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（2）除了上述保护外，对未成年人还有什么保护？

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（3）这些保护是由哪些法律专门规定的？

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（4）有的同学说：有了这些保护，我们就可以健康成长，随心所欲了。你同意吗？为什么？

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（5）我们未成年人要健康成长，应怎样进行自我保护？

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这篇短文的主要内容是( )。

A．全球沙漠化趋势加速

B．沙漠化给我们带来的损失巨大

C．沙漠化产生的主要原因

D．沙漠化趋势加速及其原因分析

（）的出现从根本上改变了人类的衣着状况。

A.文身

B.人体装饰

C.兽皮叶草

D.纤维材料

在有火源的情况下，氢气94.3%和氧气5.7%的混合物具有爆炸危险。

The United States has historically had higher rates of marriage than those of other industrialized countries. The current annual marriage (51) in the United States—about 9 new marriages for every 1,000 people—is (52) higher than it is in other industrialized countries. However, marriage is (53) as widespread as it was several decades ago. (54) of American adults who are married (55) from 72 percent in 1970 to 60 percent in 2002. This does not mean that large numbers of people will remain unmarried (56) their lives. Throughout the 20th century, about 90 percent of Americans married at some (57) in their lives. Experts (58) that about the same proportion of today’s young adults will eventually marry.

The timing of marriage has varied (59) over the past century. In 1995 the average age of women in the United States at the time of their first marriage was 25. The average age of men was about 27. Men and women in the United States marry for the first time at an average of five years later than people did in the 1950s. (60) , young adults of the 1950s married younger than did any previous generation in U. S. history.

51().

A.rate 

B.ratio 

C.percentage 

D.poll