-- card: 7571 from stack: in -- bmap block id: 0 -- flags: 0000 -- background id: 2623 -- name: -- part contents for background part 30 ----- text ----- 45 -- part contents for background part 31 ----- text ----- 14 -- part contents for background part 32 ----- text ----- 29 -- part contents for background part 13 ----- text ----- The stars of which one of the following spectral classes have the most prominent hydrogen spectral lines? -- part contents for background part 14 ----- text ----- O -- part contents for background part 15 ----- text ----- F -- part contents for background part 16 ----- text ----- K -- part contents for background part 17 ----- text ----- A -- part contents for background part 25 ----- text ----- 4 -- part contents for background part 38 ----- text ----- false