1.因为有cloudy修饰morning,这是一个多云的早晨,是一个特殊的早晨,所以需要用on,另外的例子还有on Saturday morning,都是一些特殊的早晨,所以用on.
2.in the afternoon后面的that是引导一个从句the weather turned fine,that后面的从句修饰前面的afternoon,也就是天气变晴朗的那个下午.
3.这里填sitting是省略了who is的用法,也就是lovely little who is sitting on...,所以要用现在进行时
4.It was lucky for me to do这是一个固定用法
5.the picture of sth也是固定用法,...的照片
6.stranger陌生人
7.the photo要表示特指,那张在我相机里面的照片
8.gave me给我的意思
9.had promised已经保证了,这里是在过去保证的,所以过去完成时
10.that也是引导从句,This morning I received a message back saying that they are very happy with the lovely photo of their daughter and a lovely memory of the day,因为and是并列结构,所以你可以这样看.