immature

"The conflict between the government and the rebels began three years ago."

"Separate the articles from the headings."

"The liftoff will occur in exactly twelve seconds."

"My sister is very helpful, especially when it comes to organizing things. "

"He listened carefully to his mother's concerns, feeling sorrowful about her disappointment. "

"The premature arrived at the neonatal intensive care unit very fragile. "

"The child's childish tantrum in the supermarket was embarrassing for his parents. "

"My baking skills have developed significantly since I started taking the online course. "

"The zookeeper fed the giraffes their lunch of fresh leaves. "

"untimely remarks"

"At the zoo, we saw a family of gorillas knuckle-walking through their enclosure. "

"There was an enclosure with the letter — a photo."