龙门起重机的支腿下部均安有防风装置（）。 A.阻风器 B.制动器 C.夹轨器

A new school term begins, Is anything new at your school? Sichuan students are getting an extra (额外的)hour to sleep in the morning.

This year, Sichuan schools decided that students should start classes later. This should help them feel less tired, For Junior high schools, the first classes will begin no earlier than 8:30 am.

The changes have made students happy.

Liu Xian, 15, said his class was excited by the news on the first day of school. “It’s so good we can get up later!” said Liu.

Liu studies in Chengdu No.4 Middle School. He used to get up at 6:40 am. Now he can get up at 7:40 am because class doesn’t start until 8:40 am.

Wu Hongli, 15, said the new timetable is good for her health. “I used to drink coffee every night or I would feel to sleepy to finish my homework, ”said Wu. “Now I can finish it without coffee.”She used to get up at 6:30 am. Now she can get up at 7:30 am.

Wu Hongli’s mother was happy, too. She thought more sleep would help her daughter grow taller.

But some parents worried that more sleep would mean less learning. There used to be five classes in the morning. Now there are only four.

Many teachers, though, say the changes will help students learn better.

“Students used to doze(瞌睡)for the first two classes in the morning,”said Wu Zongping, an English teacher at Chendu No.12 Middle School. “But now they look fine and they learn much better than before.”

小题1:What made the Sichuan middle school students happy?

A．The new school term began.

B．Their schools took on a new look.

C．They felt a little bit tired.

D．They could get up later.小题2:In the new term, the first class in the morning in middle schools started at about          .

A．7:00

B．7:30

C．8:00

D．8:40小题3:Why was Liu Xian excited at the news on the first day of school?

A．There were many changes in his school.

B．He could sleep one more hour in the morning.

C．He could study in Chengdu No.4 Middle School.

D．He would have only five classes in the morning.小题4:What did the teachers think of the changes of the school timetable?

A．They didn’t like the changes.

B．They could use the timetable more easily.

C．They spoke highly of the changes.

D．They looked fine when they taught.

2011年11月1日，我国“神舟八号”发射成功，并分别在11月3日和14日与“天宫一号”进行精确交会对接。这为中国突破和掌握航天器空间交会对接关键技术以及下一步建设载人空间站奠定基础、积累经验。这表明[ ]

①正确的经验能促进客观事物的发展②伟大事业的成功要求把尊重客观规律和发挥主观能动性结合起来③实践基础上的认识具有反复性、无限性和上升性④科学实验是为了掌握事物的本质和规律  

A．①③    

B．②④    

C．③④    

D．①②

某房地开发公司与另一企业签订了土地使用权转让合同，土地总价款3000万元，房地产开发公司向企业先支付了700万元订金。此后由于该地区投资环境改善，该企业未履行土地使用权转让合同，则该企业应向房地产开发公司返还1400万元。( )

GN型蓄电池爬碱严重的原因有哪些？

对于理想溶液,相对挥发度α等于两个组分蒸汽压之比。