问题 选择题

小蓝参加实验考查时,抽中了“观察血细胞”的实验,其显微镜的正确操作顺序是

①放置血涂片   ②观察   ③安装目镜和物镜   ④对光

A.①②③④

B.②③④①

C.③④①②

D.④①②③

答案

答案:C

题目分析:光学显微镜的使用步骤:

1、取镜和安放

①右手握住镜臂,左手托住镜座.

②把显微镜放在实验台上,略偏左.安装好目镜和物镜.

2、对光

①转动转换器,使低倍物镜对准通光孔.注意,物镜的前端与载物台要保持2厘米的距离.

②把一个较大的光圈对准通光孔.左眼注视目镜内,右眼睁开,便于以后观察画图.转动反光镜,看到明亮视野.

3、观察

①安装装片:把所要观察的载玻片放到载物台上,用压片夹压住,标本要正对通光孔.

②调焦:转动粗准焦螺旋,使镜筒缓缓下降,眼睛看着物镜以免物镜碰到玻片标本,直到物镜接近载玻片.这时左眼向目镜内看,同时反向转动粗准焦,使镜筒缓缓上升,直到找到物象,物象不清晰,再调节细准焦螺旋,使物象更加清晰.

最后整理实验台.

综上所述,使用显微镜的正确操作步骤应该是:③安装目镜和物镜、④对光、①放置血涂片、②观察;

故选C。

阅读理解

Clothes play a critical part in the conclusions we reach about who people are, who they are not, and who they would like to be. They tell us a good deal about the wearer′s background, personality, status, mood, and social outlook.

  Since clothes are such an important source of social information, we can use them to influence people′s impression of us. Our appearance takes on particular significance in the initial phases of interaction. An elderly middle-class man or woman may be alienated (疏远) by a young adult who is dressed in an unconventional manner, regardless of the person′s education, background, or interests.

  People tend to agree on what certain types of clothes mean. Adolescent girls can easily agree on the lifestyles of girls who wear certain outfits (套装), including the number of boyfriends they likely have had and whether they smoke or drink. Newscasters and announcers on TV are considered to be more convincing, honest, and competent when they are dressed conservatively. College students who view themselves as taking an active role in their interpersonal relationships say the costumes they wear change the way they feel about themselves and how they act. Perhaps you have used clothing to gain confidence when you face a stressful situation, such as a job interview, or a court appearance.

  In the workplace, men have long had well-defined role models for achieving success. It has been otherwise for women. A good many women in the business world are uncertain about the appropriate mixture of “masculine”(男性)and “feminine”(女性)characteristics they should convey to men.

  Male administrators tend to judge women more favorably for managerial positions when the women display less “feminine” grooming (打扮)— shorter hair, moderate use of make-up, and plain tailored clothing. As one male administrator confessed, “An attractive woman is definitely going to get a longer interview, but she won′t get a job.”

57. According to paragraph two, an elderly middle-class man and     unconventionally-dressed young man are unlikely to____.

A. understand each other's lifestyle

B. share the same background or interests

C. influence their impressions of each other

D. interact in a positive way

58. The author uses the newscasters' example to show the idea that____.

A. certain clothing gives people more confidence

B. clothes have nothing to do with one's abilities

C. we tend to label people by their clothes

D. competent people always dress conventionally

59. Men's professional clothing can best be described as "_____".

A. conventional                B. individualistic

C. out-of-date                 D. changeless

60. How should professional women dress according to the passage?

A. They must be dressed conservatively.

B. They don't have a certain dressing style to follow.

C. They choose either masculine or feminine clothing.

D. They can't wear unconventional outfits.

单项选择题