- 问题详情:ThefirsttelegraphcablewaslaidundertheseabetweenEnglandandFranceinesaremuch 1andheavierthantelegrapheareanumberofreasonsforthis:onereasonisthatthesaltwateroftheseaharms 2 telegraphwires,andsotheyhavetobe3 ,anotheristhat,becauseelectricity4...
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