皮皮学，免费搜题
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【简答题】
Digital cameras are hot. Every technology and photography lover, it seems, either has a new digital camera or is thinking about getting one. If you're in the latter category, you'll find that it's easy to be confused by the array(一系列) of choices available. Here's an overview of what to look for when you shop for your first digital camera.
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【简答题】集中联锁区,调车信号开放后,不得随意关闭,取消(变更)调车进路。信号开放后,须取消(变更)调车进路时,车站值班员(信号员)应先通知调车指挥人,确认()后,再关闭调车信号机,取消(变更)调车进路。