如何在两个线程中打印句子？

import threading

class PrintThread(threading.Thread):
    def __init__(self, sentence):
        threading.Thread.__init__(self)
        self.sentence = sentence

    def run(self):
        print(self.sentence)

# 创建两个线程，分别打印句子1和句子2
thread1 = PrintThread("This is sentence 1.")
thread2 = PrintThread("This is sentence 2.")

# 启动线程
thread1.start()
thread2.start()

# 等待两个线程执行完毕
thread1.join()
thread2.join()