The phrase "announcements were placed" is correct and usable in written English.
It can be used when referring to the act of making announcements available or visible in a specific location or context.
Example: "The announcements were placed on the bulletin board for all students to see."
Alternatives: "announcements were posted" or "announcements were displayed".
Therein, every weekend, you will find the Vows section, in which gushing wedding announcements are placed, with details of where the bride's parents have a second home, which Upper East Side private members' club the groom's stepmother belongs to and for how long his father has been a partner at Goldman Sachs.
When an agency such as the FDA announces a new regulation, the announcement is placed in the Federal Register, the official compilation of all federal regulations.
Before the U.S. EPA paper "Health Effects of Airborne Lead," released in late 1972, an announcement was placed in the Federal Register and widely circulated in the scientific community requesting responses to seven questions (U.S. EPA 1972c), which were formulated by Bridbord.
A recruitment announcement was placed in Baby Hui's email listserve/newsletter. Inclusion criteria were sedentary (i.e., not doing more than 30 minutes a week of moderate or vigorous physical activity), 18 45 years of age, postpartum 3 months to 12 months, free of chronic diseases, not pregnant, and free of medical conditions that would limit moderate intensity PA.
He had started as 2/1 favourite with bookmaker William Hill, but betting was suspended before the announcement because 100% of the wagers were placed on his garden winning.
Posters were placed in the antenatal clinics and formal announcements made at the daily antenatal clinic to inform women about the study.
Some important announcements will be placed here and many will be made on Piazza.
"The emphasis at NSF," the announcement says, "will be placed on integration of the cognitive sciences, social and economic sciences, and engineering in service of insights into healthy functions of brain, cognition, and behavior".
Birth announcements in those papers are placed by the state Department of Health, not the family.
