【简答题】关系数据库中,当运用Transact-SQL语句创建主键时,可以是()。A. create table table1(column1 char(13) not null primary,column2 int not) on primary; B. alter table table1 with notcheck add constraint [PK_table1] primary key non...
【单选题】Mental Retardation (智力迟钝) Mental retardation is a condition in which people have lower than normal intelligence and are unable to function at the level expected for their age. People with mental retar...
A.
was born prematurely.
B.
has lower than normal intelligence.
C.
has low intelligence and low daily living skills.
D.
has normal intelligence but difficulties in learning.