在△ABC中，“A＞B”是“sinA＞sinB”成立的[ ] A．充要条件 B．

Students who date (约会）in middle school have significantly worse study skills, are four times more likely to drop out of school and report twice as much alcohol and tobacco use than their single classmates, according to new research from the University of Georgia.

"Romantic relationships are a trademark of adolescence，but very few studies have examined how adolescents differ in the development of these relationships," said Pamela Orpinas，study author and professor in the College of Public Health and head of the Department of Health Promotion and Behavior.

Orpinas followed a group of 624 students over a seven-year period from 6th to 12th grade.

Each year, the group of students completed a survey indicating whether they had dated and reported the frequency of different behaviors, including the use of drugs and alcohol. Their teachers completed questionnaires (调查表）about the students* academic efforts. He found some students never or hardly ever reported dating from middle to high school, and these students had consistently the best study skills according to their teachers. Other students dated infrequently in middle school but increased the frequency of dating in high school.

"At all points in time, teachers rated the students who reported the lowest frequency of dating as having the best study skills and the students with the highest dating as having the worst study skills,'¹ according to the journal article. Study skills refer to behaviors that lead to academic success such as doing work for extra credit being well organized, finishing homework, working hard and reading assigned chapters.

"Dating a classmate may have the same emotional complications of dating a co-worker," Orpinas said, "when the couple break up. they have to continue to see each other in class and perhaps witness the ex-partner dating someone else. It is reasonable to think this could be linked to depression and divert (转移）attention from studying.”

^4tDating should not be considered a ceremony of growth in middle school，”Orpinas concluded.

小题1:According to the passage, students who date in middle school may_____

A．have poorer academic performances

B．be more likely to hurl others

C． enjoy better school lives

D．are less likely to use alcohol and tobacco小题2:When doing his study, Orpinas_____.

A． followed a group of students of 6th and 12th grade

B． completed a survey and a report each year

C． completed questionnaires about the students’ academic efforts

D． found that the students’ study skills have connection with their frequency of dating小题3:Study skills may include the following behaviors and qualities Except_____

A．being diligent

B．bcing well organized

C． being kind and helpful

D．finishing assigned schoolwork小题4:What can possibly happen to the school couples after they break up?

A． They don’t want to see each other any longer.

B． Their attention to studying will be affected.

C． They will miss their ex-partners sometimes

D． They will think it，s reasonable Io get depressed.小题5:Orpinas’  attitude towards dating in middle school is_____

A．supportive

B．positive

C．negative

D．indifferent

某班进行“建设生态文明”专题复习，老师指导同学们根据主题词“收集和筛选时政材料、梳理和整合考点知识、分析和解决实际问题”。请完成他们的学习任务。

（1）理解以下主题词与时政材料之间的逻辑关系，将代表主题词的序号填写在下列表格中最适合的位置上，每个序号只填一次。

①再生利用，循环发展   ②建设生态文明，实现中 * * 永续发展 

③节能减排，低碳发展   ④厉行节约，反对浪费

序号	时政材料	主题词
1	国家在“十二五”期间将实现节约能源6.7亿吨标准煤，到2015年，万元国内生产总值能耗要比2010年下降16%，全国氨氮和氮氧化物排放总量要比2010年各减少10%。
2	广东省要求，企业应当依法建立资源节约和循环利用管理制度，提升技术和管理水平，从生产源头上减少能源资源消耗量，实现减量化。
3	实施“光盘行动”以来，仅南京的30所中小学，一个月就减少剩饭9万斤；有学校以此为契机开展相关行动，倡导进饭堂请光盘、离课室请关灯、洗手后请关水龙头等。

（2）请分别分析上述时政材料中各举措的现实意义。

某机电公司承接某化工厂的设备安装工程。设备安装需用起重机吊装就位，吊装施工前，机电公司按照工程需要，认真选择钢丝绳、滑轮组和卷扬机。滑轮组选用H系列滑轮组，滑轮组跑绳选用安全系数适合的钢丝绳，并对卷扬机进行容绳量校核。所有吊具选用完毕后，进行吊装工作。

起重工程中一般采用( )。

A．慢速卷扬机

B．快速卷扬机

C．电动卷扬机

D．手动卷扬机

《尚书》从尧舜禹时代开始到哪个时代结束（）

A、秦始皇时期

B、周武王时期

C、春秋中期秦穆公时期

D、西汉武帝时期

产业结构就其基本内容来看包括( )。

A．产业构成

B．产业发展水平

C．产业间的技术经济联系

D．产业优化

E．产业升级