i was b_ on a cool spring morning

i was b_ on a cool spring morning on a cool morning为什么不是on the cool morning I was born（）a warm spring morning（）1997 in Panxian、 I was born（）a warm spring morning（）1997 in Panxian 阅读理解It was a beautiful spring morning.There were no clouds i a cool morning前面用in 还是on The little girl was born a warm spring morning My aunt arrived here ( on ) a warm spring morning. i was born (on)a cold winter morning(on)january,1948 对不? 英语翻译A Spring MorningIt was early in the spring morning.The s Tom was having a bath in the b_ when I called him When I was walking on campus this morning,a ball hit my head