严复翻译的《天演论》，其原文的题目是（）
Fishis________andexpensiveatthistimeoftheyearinthisarea.
TheaveragelifeexpectancyoftheRedIndiansis________.
Weweretoldthatthestonefigure_______backtothe16thcenturywasofgreatvalue.
TheMississippi,whichissometimescalled________,hasplayedavitalroleinthehistoryoftheUnitedStates.
