Answer:
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The Arecibo message and the beacon in the galaxy were broadcast in binary code because binary is a universal language that can be easily understood by any intelligent beings, regardless of their language or culture. Binary code consists of only two symbols, 0 and 1, which can be used to represent any information, including letters, numbers, and instructions. This makes binary an ideal choice for transmitting messages over vast distances, as it is less prone to errors and can be decoded with a high degree of accuracy.