CEDAR RAPIDS — High school students will takeover the city’s social media pages on Friday.The initiative could help city officials crack the code of how to reach their youngest residents. The students from Iowa BIG won’t have free rein, but have created the photos, videos and comments to be shared on the city’s Twitter, Facebook and Instagram accounts on Friday, said Maria Johnson, the city spokeswoman who led the initiative and runs the city’s social media accounts.“Our social media is very much geared to adults who live in the city,” Johnson said.