下列有关米力农的叙述正确的是（） A.是一种新型的非苷、非儿茶酚胺结构的强心药 B.

冬天冻冰的衣服放在室外-5℃的环境中也能干，这属于______现象，窗户上的“冰花”是______现象．

阅读下面的短文，然后将划线部分句子译成汉语或英语。

To many students, joining social media (社交媒体) “circles” is now more important than making new friends in real life. And it’s easy. If you have a cell phone, you can download apps. Sina Weibo, WeChat and QQ are the most popular among them.

“I love to check my friends’ updates (更新).小题1: I also enjoy news and jokes shared on social media,” said Ou Wei, 14, from Hongling Middle School in Shenzhen. While enjoying these, Ou makes himself stay from real life. “I love playing the games on WeChat, but have no interest in playing flying chess with my classmates,” said Ou Wei.

小题2: Zhang Le（张乐）, 14, from No. 12 Middle School in Shanghai, said that social media has affected their normal life a lot. Recently his school held a basketball match, and a student hurt his leg.小题3:大多数学生忙着发送关于这个事故的照片而不是帮助他。“I think they need to learn to balance their real and online lives,” said Zhang.

小题4:What worries parents and teachers is safety.“Many students are happy to tell their interests and personal information to their social media ‘friends’. 小题5: 据报道这种信息可能会给他们带来危险,” said Han Songjun, a teacher at Hongling Middle School.For example, WeChat’s shake-shake function (功能) allows users to connect to other users close by. But police authorities warn about the risks of socializing in this way. “Be careful. Do not use the locating (定位) function in any app, do not give your name, and do not post the photos of your residential area (小区),” said Han.

我国经济与社会发展要坚持的“75个必须”原则是在( )中提出的。

A．温 * * 2004年3月5日《政府工作报告》

B．《全面建设小康社会，开创中国特色社会主义事业新局面》

C．《国民经济和社会发展“九五”计划和2010年远景目标纲要》

D．《中 * * 关于制定国民经济和社会发展第十一个五年规划的建议》

《工业企业厂界噪声标准》(GB 12348—90)的规定，工作环境的噪声最高不得超过( )。

A．105 dB

B．110 dB

C．115 dB

D．120 dB

位置水头Z表示的是单位重量流体从基准面算起，所具有的（）。

A.位置动能

B.位置势能

C.压力动能

D.压力势能