"A century later" by imtiaz dharker analysis

Based on context, the word “insoluble”most likely means?

Read the excerpt from a history of the world in 100 objects. power is usually not willingly given, but forcefully taken; and in both europe and america the nineteenth century was punctuated by political protest, with periodic revolutions on the continent, the civil war in america and, in britain, a steady struggle to widen the suffrage. what would be a benefit of reading this text rather than listening to an audio version of it? the reader could analyze the text features in the excerpt. the reader could visualize the description given. the reader could set his or her own pace and reread parts for clarity. the reader could hear the sounds of the political protest.

Which would be the most credible source for researching the effects of smoking? letter from your grandfather web page about someone’s lung cancer report prepared by a tobacco company research article in a scientific journal