题目

The first two and a half years of American control of the Panama Canal were devoted only to preparation for human living. Energies were committed to establish suitable houses, hotels, and kitchens. Food supplies were built up and the ability of the existing Panama Railway system was increased. In addition, a large Panama Canal labor（港口） force was enrolled (招收) and organized under a civil government. With all this activity, the need for improved sanitation(卫生) soon became obvious . Improving the unclean conditions was one of the greatest difficulties in building the Panam看图回答问题。                                           某地2004年二、三季度气温变化情况统计图 1．哪个月气温最高？哪个月气温最低？2．哪两个月间气温上升得最快？哪两个月间下降得最快？  3．这个问题我来提：从九月到年末，气温会怎样变化？