这阻塞了主线程但是在另一个线程上执行代码。

This blocks the main thread but executes the code on another thread.

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它是启动过程中隐式创建的主线程，执行main方法。

It's the main thread that is implicitly created on process startup and executes the main method.

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并行性是通过运行主线程为每一个任务调度执行的子线程而实现的，这样任务就会并发执行，而每一个线程是同步执行任务的。

Parallelism is introduced by running the main thread scheduling child threads for each task so that the tasks execute concurrently while each thread execute the task synchronously.

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