firefly (Luciola cruciata); lightning bug; glowworm
fluorescent lamp; fluorescent light; person who is slow to react; someone slow on the uptake
diligence in studying (e.g. continuing to study even in such poor light as offered by a firefly or that reflected by snow); diligent study
fluorescent lamp; fluorescent light; person who is slow to react; someone slow on the uptake
highlighter; highlighter pen