The phrase "acted as hosts" is correct and usable in written English.
It can be used when describing individuals or groups who are serving in the role of a host for an event or gathering.
Example: "During the conference, the volunteers acted as hosts, guiding attendees to their seats and providing information about the schedule."
Alternatives: "served as hosts" or "functioned as hosts".
They gradually gained great power, for the Ephraimites acted as hosts to the tribal assemblies and had within their borders such religiously important centres as Shiloh and Bethel.
Finally, during most of Phanerozoic time (i.e., about the past 541 million years), the nuclei have remained stable and have acted as hosts around which the tectonic collages have accumulated in the Phanerozoic orogenic zones.
When the 1997 movie "Gattaca" came out, depicting a dystopia where genetic determinism has been taken to an extreme, its Web site forums acted as hosts for debates arguing whether moviegoers would prefer to design their own child or "roll the genetic dice".
When these weekends began, the four of us who acted as hosts thought it was our duty to create themes to guide the weekends.
The guys smiled and shook fans' hands as they acted as hosts, hyping up the magic that was about to happen during their set.
The Russian Orthodox Church acted as host to desultory discussions between representatives of the parliament and the president.
Their meeting was followed by a lunch at which the head of the North Korean Workers Partyy acted as host.
Mr. Mubarak, who acted as host to the meeting, put himself squarely behind the Palestinians in his opening remarks.
There he has led a big band, owned a Moscow jazz club and acted as host of a television program.
At home, Mr. Sanchez ordered takeout and acted as host, making sure everyone had enough fried chicken and egg rolls.
Later, he washed dishes in a wooden tub in the kitchen, acted as host, waited tables, mopped floors and shucked clams.
