【单选题】_____ provide a description of the data characteristics and the set of relationships that link the data found within the database.
【单选题】public class class1 { private string _Data=””; public string Data{set{_Data=value;}} } 创建该类的对象obj后,下列哪个语句是合法的( )
A.
ojb.Data=”It is funny”;
B.
Console.Write(obj.Data);
【单选题】下列关于数据集Data Set的说法,错误的是()
A.
在Data Set中可以包含多个Data Table
B.
Data Set可以简单地理解为一个临时数据库
C.
在与数据库断开连接后,Data Set中的数据会消失
D.
Data Set是数据源中检索到的数据在内存中的缓存
【单选题】Assuming that the data set Company.USA has five or more observations, what is the result of submitting the following program? data work.getobs5(drop=obsnum); obsnum=5; set company.usa(keep=manager pay...
D.
a data set that contains one observation
【单选题】混合气体的密度可按各种气体()的百分数来计算。
【单选题】For data transmission to be successful,sending and receiving devices must follow a set of communication rules for the exchange of information. These rules are known as( ).
【单选题】混合气体的密度可按照各种气体()的百分比数来计算。