智力测验题(英语)I only have two minutes to catch the train,but there are two miles from my house to the train station.If I go the first mile at the rate(速率)of 45 miles per hours ,at what rate must I go the second mile in order to cat

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智力测验题(英语)
I only have two minutes to catch the train,but there are two miles from my house to the train station.If I go the first mile at the rate(速率)of 45 miles per hours ,at what rate must I go the second mile in order to catch the rain?
A.30m.ph B .45m.ph C.60m.ph D.90m.ph

在前一英里中,速度是3/4,用时4/3分,后一英里需用时2/3分,计算,速度是90英里/小时,选D