同学你好，该知识点来自沪江网校《英语零基础直达大学六级【8月班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~
Such a messenger, receiving our radio and television signals, might well re-transmit them back to its home-planet,
这种自动化信息装置，在接收到我们的无线电和电视信号后，完全有可能把这些信号发回到原来的行星。
although what impression any other civilization would thus get from us is best left unsaid.
至于其他文明行星对我们地球会有什么印象，还是不说为好。

although在这里表示“不过，然而”，比如
I felt he was wrong, although I didn't say so at the time.
我觉得他错了，不过我当时没有说出来。

祝同学学习进步~