What is Nellie Bly progressive cause?

Which of the following statements is true about germany's use of u-boats?

Which would make the best heading for this list of notes about the migration of african-americans during the reconstruction era?

Historians have recently discovered a historical journal published in the early twentieth century. the journal contains facts based on original sources about the downfall of the early byzantium empire. historians consider this long-lost journal to be a breakthrough in their understanding of the byzantium empire. based on this information, the journal is a source.