Which of the following strategies can be used to deal with China's ecological envirnment problems ( ) A: Changing the economic development mode. B: Encouraging scientific and technological innovation and developing clean energy. C: Improving the judicial safeguard mechanism. D: Vigorously developing industry.

JDK是整个JAVA的核心，包括了Java运行环境JRE（Java Runtime Envirnment）、一堆Java工具（javac/java/jdb等）和Java基础的类库（即Java API 包括rt.jar）。