公钥密码体制有两种基本的模型：一种是加密模型、另一种是 【4】 。

船舶失踪构成保险责任的条件是()。

A.船舶的失踪是由于保险责任范围的原因引起的

B.失踪满3个月以上

C.失踪满6个月以上

D.船员和船舶同时失踪

E.船舶在航行中的失踪

在进行纠接式绕组的纠接连接以前，检查所要焊接的两根导线是否是纠接线的方法是（）。

A.两根导线从纠接单元的两段中分别引出，且在线段中位置相同

B.两根导线从纠接单元的两段中分别引出，且互不相通

C.两根导线从两个纠接单元中分别引出，且在线段中位置相同

D.两根导线从纠接单元的两段中分别引出，且互相导通

羽状边打磨距凹陷部位至少要（）cm。

A．1～2

B．2～3

C．3～5

D．7～8

Due to the increasing number of violence acts produced in schools all over the world，more and more parents prefer to have their children educated at home rather than at school. This way they can assure their safety and well-being，although teachers and school representatives are trying to improve the situation in schools by increasing the number of the persons in charge with the safety of the students．

The main reason for violence acts are the films and cartoons that fill the children’s time．They want to do everything．they watch on TV and never think at the consequences，and they may hurt a classmate or a teacher．

On the other hand, parents are not fully satisfied with the children’s results obtained in classes and they consider private classes would have better results．

When a teacher has to watch 30 students in class he can’t probably see what each of them is doing，how he is writing，or if he understands the explanations．At home the teacher can explain in details everything the child doesn’t understand as many times as he considers proper．

And many times．the child grows fond of the teacher at home，who becomes his best friend，and who helps him whenever he needs someone to talk to．    

However, the best solution would be a mixture between the education received at school and that at home，because school makes children communicate and socialize．Keeping a child at home for fear there might happen something bad to him．only makes the child’s character weak and prevents him from knowing what real life is．Staying in a crystal ball only does harm to the child．

All in all．schools have been created to help children，not to harm them，so it’s best to keep children in these special places，where they learn，laugh，have fun and make new friends．

小题1:The writer’s purpose in writing the text is to          ．

A．teach parents the ways to keep theft children safe

B．show solutions to developing children’s character

C．explain the main reason for violence acts in schools

D．analyze an education problem and give opinions小题2:Parents prefer to have their children educated at home because the following EXCEPT that______.

A．More and more violence acts occur in schools

B．Parents want to improve their Children's grades

C．Parents are concerned about their children’s safety

D．The education system is far from satisfactory小题3:What does“a crystal ball”in the passage refer to?

A．A toy that can be used for entertainment．

B．A safe and comfortable environment．

C．An object that is made of crystal．

D．A setback that is hard to overcome．小题4:We call infer from the passage that          ．

A．violence TV programs have bad effects on children’s behavior

B．The teacher at home is more patient than the teacher at school

C．Children today are weak from lack of sense of right and wrong

D．There are too many students in class for a teacher to teach小题5:Which of the following might be the best title of the passage?

A．Advantages and Disadvantages of Private Classes

B．Who is to Blame, Parents or Schools?

C．Which is Better, School Study or Home Study

D．The Relationship between Teachers and Children

以下哪一项不利于药物的眼部吸收（）

A.降低滴眼液表面张力

B.降低制剂黏度

C.减少给药剂量

D.减少刺激性

E.将毛果云香碱滴眼剂pH调至7.0