这里第一个but是个连词,there are few Chinese but have heard of the Great Wall这句话单独看.there are few Chinese 是个完整的句子,后面but引导的是一个从句.所以but是连接主句和从句的连词.在这里but表示否定意...是不是though后面的大长句子都是many of them haven't been there yet.的状语？是的。这下明白了吗？