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问题 选择题

下图表示新鲜绿叶的四种光合色素在滤纸上分离的情况，以下说法正确的是

[ ]

A．提取色素时加入碳酸钙是为了防止滤液挥发

B．水稻在收获时节，叶片中色素量的变化是(甲+乙)<(丙+丁)

C．四种色素都能溶解在层析液中，乙色素的溶解度最大

D．四种色素中，丙和丁主要吸收的是红光

答案

答案：B

单项选择题

Object-oriented analysis (OOA) is a semiformal specification technique for the object-oriented paradigm. Object-oriented analysis consists of three steps. The first step is (71) . It determines how the various results are computed by the product and presents this information in the form of a (72) . and associated scenarios. The second is (73) , which determines the classes and their attributes; Then determine the interrelationships and interaction among the classes. The last step is (74) , which determines the actions performed by or to each class or subclass and presents this information in the form of (75) .

（72）处应填（）。

A．collaboration diagram

B．sequence diagram

C．use-case diagram

D．activity diagram
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单项选择题

下述程序为一数据段，正确的判断的是( )。
DATA SEGMENT
X DB 332H
FIRST=1
FIRST EQU2
ENDS

A．以上5条语句为代码段定义，是正确的

B．语句3，4分别为FIRST赋值，是正确的

C．语句2定义变量X是正确的

D．以上没有正确的答案
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