帮我解释下后半句He fell into the water,much to the entertainment of the onlookers.

问题描述:

帮我解释下后半句He fell into the water,much to the entertainment of the onlookers.
意思我知道,但是后半句是个什么语法,我没看明白.

to one's entertainment,跟to one's surprise一样的.