与全口义齿稳定性最密切的表面是（） A.平面 B.磨光面 C.咬合面 D.组织面 E

Is it true ?

1．Wearing the wrong type of glasses will do harm to your eyes .

This is not true for adults , although incorrect glasses may not be good for children under 10 . Ready-made glasses , and not wearing when you should , won’ t do harm to your eyes , but you may see better with glasses that are specially made for you .

2．Watching too much television is bad for you eyes .

This is not true. People with easily affected eyes may find they get red and aching from staring at a fixed distance for long periods , but there won’ t be any lasting effects .

3. Carrots will help you see in the dark. Carrots are rich in beta-carotene, which the body can change into vitamin A, too little of which can cause night blindness. However , people in most countries don’ t need to worry about vitamin A deficiency（缺乏）, night blindness is more likely to be connected with another vision problem .

小题1:According to the passage , which of the following is TRUE ?

A．Ready-made glasses will do harm to one’s eyes.

B．Wearing the wrong glasses may do harm to children’s eyes.

C．The human body is unable to change beta-carotene into vitamin A.

D．Watching less television may do harm to children’s eyes.

小题2:Night blindness is most likely caused by _____ .

A．staring for long periods

B．too much beta-carotene

C．not enough vitamin A

D．vision problems小题3:According to the article , eye problems can be corrected by _____ .

A．wearing specially-made glasses

B．performing eye exercises

C．cutting back on television

D．eating more carrots小题4:Watching too much television can cause _____ .

A．night blindness

B．lasting eye problems

C．a number of vision problems

D．eye trouble for a limited time小题5:The main purpose of this article is to _____ .

A．tell people of the importance of their eyes

B．tell people how to protect their eyes

C．tell people to have more carrots

D．tell people something more about their eyes

2007年12月10日，东北新闻网指出，面对肉价飙升引发的结构性物价上涨，国家应该及时提高社会保障标准，保障居民生活必需品供应。这样做 [ ]

①体现了国家改革收入分配制度和规范收入分配秩序的要求②体现了效率是公平的基础，公平是效率的前提③有助于防范通货膨胀④有利于让社会保障对象分享经济发展成果

A．①②

B．①④

C．②③

D．②④

麻黄碱主要用于

A．神经性休克
B．轻症支气管哮喘
C．心源性休克
D．房室传导阻滞
E．过敏性休克

两台离心泵的流量、扬程分别用Q₁、H₁和Q₂、H₂表示，当它们串联工作时，则流量满足Q_总=Q₁=Q₂，扬程应满足（）。

A、H_总=H₁－H₂

B、H_总=H₂－H₁

C、H_总=H₁=H₂

D、H_总=H₁＋H₂

卷积码是由（）组成的