Sentence:  Like most human <WSD>activities</WSD>, ballooning has sponsored heroes and hucksters and a good deal in between. For every dedicated scientist patiently recording atmospheric pressure and wind speed while shivering at high altitudes, there is a carnival barker with a bevy of pretty girls willing to dangle from a basket or parachute down to earth. 
Meaning of the word marked with <WSD> tags:  Something done for pleasure or entertainment, especially one involving movement or an excursion.