写字既是一项重要的语文（），又是一个人（）的体现。

日本特大地震造成福岛第一核电站1号机组内氢气爆炸，请回答有关问题：

（1）我国已检测到因日本核泄漏而释放的放射性碘131，说明构成物质的微粒具有______的性质。

（2）日本政府曾向当地居民发放碘片，适量服用碘片可避免人体再吸收放射性元素碘131，从而减少______（填序号）疾病的发生。

①甲状腺　②龋齿　③骨质疏松

（3）元素周期表中碘元素的某些信息如图所示，则关于碘131（131为该原子的相对原子质量）与碘127的说法正确的是______（填序号）。

①属于同种元素　②原子序数都是53　③原子质量相同

（4）地震破坏了机组内的冷却系统，核燃料棒外由锆（Zr）合金做的包壳被加热到1200℃以上时，锆与水发生反应生成氧化锆（ZrO₂）和氢气，氢气与空气混合燃烧爆炸．请写出上述两个反应的化学方程式_______________、_______________。

B

A 17-year-old boy, caught sending text messages in class, was recently sent to the vice principal's office at Millwood High School in Halifax, Nova Scotia. The vice principal, Steve Gallagher, told the boy he needed to focus on the teacher, not his cellphone. The boy listened politely and nodded, and that's when Mr. Gallagher noticed the student's fingers moving on his lap. He was texting while being scolded for texting. “It was a subconscious act,” says Mr. Gallagher, who took the phone away. “Young people today are connected socially from the moment they open their eyes in the morning until they close their eyes at night. It's compulsive.”

A study this year by psychology students at Covenant College in Lookout Mountain, Ga., found that the more time young people spend on Facebook, the more likely they are to have lower grades and weaker study habits. Heavy Facebook users show signs of being more socialable, but they are also more likely to be anxious, hostile or depressed. (Doctors, meanwhile, are now blaming addictions to 'night texting' for disturbing the sleep patterns of teens.)

Almost a quarter of today's teens check Facebook more than 10 times a day, according to a 2009 survey by Common Sense Media, a nonprofit group that monitors media's impact on families. Will these young people get rid of this habit once they enter the work force, or will employers come to see texting and 'social-network checking' as accepted parts of the workday?

Think back. When today's older workers were in their 20s, they might have taken a break on the job to call friends and make after-work plans. In those earlier eras, companies discouraged non-business-related calls, and someone who made personal calls all day risked being fired. It was impossible to imagine the constant back-and-forth texting that defines interactions among young people today.

Educators are also being asked by parents, students and educational strategists to reconsider their rules. “In past generations, students got in trouble for passing notes in class. Now students are adept at texting with their phones still in their pockets,” says 40-year-old Mr. Gallagher, the vice principal, “and they're able to communicate with someone one floor down and three rows over. Students are just fundamentally different today. They will take suspensions rather than give up their phones.”

46. The underlined word “a subconscious act” refers to an act __________.

A. on purpose     B. without realization        C. in secret         D. with care

47. Young people addicted to the use of Facebook _________.

A. are good at dealing with the social relationships and concentrate on their study

B. have high spirits and positive attitudes towards their life and work

C. have been influenced mentally in the aspects of behaviors and habits

D. are always in bad mood and have poor performance in every respect

48. Through the situation of today’s older workers in their 20s, it can be inferred that ___________.

A. the employers will not accept young people’s sending text messages

B. a cellphone is a must for today’s older workers instead of young people

C. the employers prefer older workers to young people

D. the employers will find it hard to control the interaction among young people

49. Mr. Gallagher reminds us that the students in the past and those today _________.

A. like to break rules and have the same means of sending messages

B. are always the big problem for the educators and their parents

C. like sending text messages but those today do it in a more secret and skillful way

D. cannot live without a cellphone

50. What’s the best title of the passage?

A. Teenagers and Cellphones                       B. Teenagers’ Texting Addiction

C. Employers and Teenagers                        D. Teenagers’ Education

测量准确度指______。

A．测量仪器的准确性

B．测量的误差很小

C．测量结果与被测量真值之间的一致程度

D．测量的误差与被测量真值之间的一致程度

费用优化的步骤主要有：①计算工程总费用；②确定缩短持续时间的关键工作；③计算各项工作的直接费用率；④确定间接费用率；⑤确定持续时间的缩短值。其正确的步骤是( )。

A．①——②——③——④——⑤
B．③——④——②——①——⑤
C．③——④——①——②——⑤
D．④——③——①——②——⑤

根据《建筑基坑支护技术规程》4.8.8要求，当支护结构的安全等级为一级时，抗拔承载力检测值与轴向拉力标准值的比值≥（）。

A.1.1

B.1.2

C.1.3

D.1.4