13500558 - Baby girl crawling on all fours13500300 - Baby girl laughing13503958 - Baby girl crawling with toy tractor13503441 - Baby girl sitting playing with pull along toy duck13313943 - University student sitting in classroom13313970 - University student texting on break13313954 - Smiling university student sitting13314023 - Student standing during break13313986 - Student using smartphone at seminar13313965 - Portrait of university student texting13313974 - Focused student listening during seminar13313948 - Student with book standing beside window13313966 - Two university friends looking at tablet13314003 - Student taking exam