SQL的基本表约束主要有三种形式:候选键定义、外键定义、______________定义。
参考答案:检查约束
在选择电动机的制动方式时,若单从节能的观点出发,最好选择().
A.机械制动
B.反接制动
C.能耗制动
D.再生反馈制动
One of the guidelines in writing the C code for a software tool is as follows: write code that is as clear and as simple a (76) . The C language can be difficult to read if you combine all (77) features in a single statement. Break complicated (78) into several easy to understand statements for the (79) of readability. This style helps to make your programs more (80) and error-free.
A.readable
B.reusable
C.possible
D.semantic
E.syntactic
F.constructions
G.safe
H.impossible
I.sake
J.structure