下列哪项视网膜病变不是妊娠期高血压疾病的眼底改变（） A.视网膜水肿 B.视网膜剥离

下列常见的电流中最大的是 [ ]

A．雷电的电流

B．房间灯泡的电流

C．家用空调器的电流

D．手电筒中的电流

风险题：吸食冰毒的危害是什么？

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

      Friends play an important part in our lives, and although we may take friendship for granted, we often

don't clearly understand how we make friends. While we get on well with a number of people, 1______.

      Moreover, a great many relationships come under the general term "friendship". In all cases, two people

like one another and enjoy being together, but beyond that, the degree of closeness between them and the

reasons for their interest in each other change greatly.

      At the beginning, much depends on how people meet, and on good first impressions. As we get to know

people, 2______. Although these factors are not of the greatest importance, it is more difficult to have a good

relationship with people when there is a big difference in age and background. 

     Then, 3______. Friends will stand closer together and will spend more time looking at each other than

ordinary friends. Smiles and soft voices also express friendliness, and it is because they may give the wrong

signals that shy people often have difficulty making friends. A friendly look with a wrong facial expression

can turn into an unfriendly stare, and nervousness may be wrongly understood as unfriendliness.

      Some friendly relationships are a result of argument and discussion, but it is usual for close friends to

have the same ideas and beliefs, the same opinion and interests. The more closely involved people become,

the more they depend on each other. And 4______. Equally, friends have to learn to make allowances for

each other, to put up with annoying habits, and to accept differences in opinion.

      In contrast with marriage, 5______. But the support and understanding that results from shared experiences

and affections does seem to create a close and lasting relationship.

A. we are usually friends with only a very few

B. many factors can affect friendship and relationship

C. people want to do friends favors and hate to let them down

D. argument and discussion can improve personal relationships

E. we consider things like age, race, looks,economic and social status, etc

F. we pay attention to actual behavior, facial expression, and the way a person speaks

G. there are no friendship ceremonies to strengthen the relationship between two people

室间隔缺损和动脉导管未闭时，若临床上出现声音嘶哑，最常见的原因为

A．左心室增大，压迫喉返神经
B．肺动脉扩张；压迫喉返神经
C．左、右心室增大，压迫喉返神经
D．右心室增大，压迫喉返神经
E．左心房增大，压迫喉返神经

树木芽向上长，根往地下钻的原因是（）

A.植物养分

B.植物水分

C.植物激素

D.植物环境