需求定义包括很多内容。其中一般首先应确定的、最基本的是用户对信息系统的（）。A．性能

下图表示夏季连续两昼夜内，某野外植物对CO₂的吸收量和释放量的变化曲线图。S₁～S₅表示曲线与X轴围成的面积。下列叙述错误的是

A．图中B点和I点表示此刻该植物的光合作用强度和呼吸作用强度相同

B．图中D～E段不是直线的原因是夜间温度变化影响植物的呼吸作用

C．如果S₁+S₃+S₅>S₂+S₄，表明该植物在这两昼夜内有机物的积累为负值

D．图中S₂明显小于S₄，造成这种情况的主要外界因素最可能是CO₂浓度

一个无症状的18岁大学新生，男，在体格检查中发现血压148/90mmHg，眼底检查正常，尿蛋白++，以下哪一种情况最可能存在（）

A.肾血管性高血压

B.原发性高血压

C.肾实质性高血压

D.体位性蛋白尿

E.白大衣高血压

Good afternoon, everybody. I’m pleased to be here with you, graduates of 2007. I’m a (1) , and students often approach me with (2) . You see, we are living in a society of great changes. With the presence of (3) , the process of getting a job in today’s world has changed for (4) .
Well, how can you use new technologies to help you First, let’s look at how you (5) . The traditional method of hunting for a job in the past required first, doing research on jobs that were (6) , typically by looking in newspapers, periodicals and magazines, as well as TV ads, and (7) . Then you decided where and for what post you were going to apply, put your resume (8) in a stamped envelope, and waited anxiously for someone to (9) .
Well, today, maybe the job search and (10) are very much the same, but the tools used are much more advanced, and they (11) . In fact, technology has not so much changed the process as enhanced it. The benefit, both for (12) , is that this makes the search more open to people of (13) from all over the world. But as more people are involved, it becomes (14) for the applicant than it ever was before.
The (15) for the working world today is learning these new and (16) and combining them with the older methods people have been using for years. For example, (17) , you can research employment not just in your city, but also in your state, your country, and (18) . You can copy information from a web page and paste it into a Microsoft Word document that’s easy to (19) . In many ways, it’s easier now: Just type your job application, click, and (20) ; it gets there in an instant.

按照法律的创制和适用主体的不同，法律规范划分为（）。

A.成文法和不成文法

B.一般法与特别法

C.根本法与普通法

D.国内法和国际法

外力作用的主要表现形式有风化、侵蚀、搬运、沉积和固结成岩等。据此及下列材料完成回答下列问题。材料：与外力作用相关的部分地理事物或现象：①冲积平原和三角洲②黄土高原千沟万壑的地表形态③横断山地“水拍云崖”的雄奇壮丽景观④沙丘；上述地理事物或现象中，位于干旱地区的是（）

A、①

B、②

C、③

D、④