This photo is captioned School at Center, Lake Creek No. 5, Elta Smith - Teacher. George, Mason, Mary and Clara Ross are in this photo. It says that John Ross Jr. is absent from the photo. The photo is not dated, but George was born in 1890, and John in 1899, so I'm guessing for them to both be in grade school it would be in the vicinity of 1903. This photo is probably the entire K-8 student body at the number five school in Lake Creek Township, Calhoun County, Iowa.
I've cropped the photo to focus on Mary and Clara Ross. I believe that Mary is the third from the left and Clara is the girl just to the right of the center of the photo. I can't recognize the boys in the photo, they may be grouped in classes rather than families and I might have cropped them out to focus on Mary and Clara.
Here is the reverse side of the photo, lots of caption, but not much help as far as who is in which row. One interesting bit of trivia, notice the name Acklin in the caption. Harold Acklin Whitted is named for his mother Anna Acklin. Bill, Mary and Ruth Acklin are actually his mother's younger siblings. Anna Acklin was born in 1877 and they were born in the late 1890s. According to my notes the Acklin family had 10 children from 1877 to 1898. Even though they are not in this picture, Helen Ross and Harold Whitted probably went to this same school and eventually married in 1939.
The connection to the Brassfield surname is Clara Ross is my Great Grandmother. Her daughter married Elvis J. Brassfield.
Other surnames in this photo are Vadakin, Moore, Hiler, Heath, Rosenberg, Clark, Waugh, Savage, Gregg, Willert and Cleland.
Here is an approximate transcription of the caption. Unfortunately they are not listed in the order they are photographed. I would imagine most of these names also appear in the Lake Creek, Calhoun, Iowa census for 1900.
John Vadakin, Agnes Vadakin, Richard Moore, Bessie Hiler, Vernie Hiler, Grace Hiler, Etta Hiler, George Ross, Mason Ross, Mary Ross, Clara Ross, Lee Heath, Earl Heath, Fred Rosenberg, Bernice Rosenberg, Jern? Rosenberg, George Clark, Louisa Clark, Merle Clark, Stella Clark, Bessie Waugh, Willie Waugh, Frank Waugh, Bill Acklin, Mary Acklin, Ruth Acklin, Carl Savage, Lola Greg, Ethel Greg, Curt Greg, Paul Greg, Ruby Willert, Emma Willert, Celia Cleland, Florence Cleland.