Daily Chinese Idiom Guessing Game
To be completely devoted or focused on a single task or person.
只有一个心眼儿，没有别的考虑。
《三国志·魏志·杜恕传》免为庶人，徙章武郡，是岁嘉平元年。”裴松之注引《杜氏新书》故推一心，任一意，直而行之耳。”
She studied for the exam with single-minded dedication, ignoring all distractions.