种群数量在较长时期内维持在几乎同一水平的现象称为___________。
参考答案:种群平衡
Object-oriented DBMS integrated a variety of (81) data types-such as business procedures, graphics, pictures, voice and annotated text. Object orientation also makes a (82) to application development efficiency. It makes the data, functions, attributes, and relationships an integral part of the (83) . In this way, objects can be reused and replicated. Some leading RDBMS vendors support the concept of integrating object management capabilities with their current line of relational products. That capability enable users to the development cycle, since integrity logic and business roles no longer need to be programmed (84) each application.
A.tool
B.in
C.idea
D.contribution
E.joke
F.short
G.object
H.theoretical
I.extent
J.shorten K. real-world L. into
关于学习,杜威反对机械的记忆和训练,倡导学生应该在“做”中学。