Quadtrees
四元树
🗣️ 情景例句
They are constantly quarreling.
他们时常吵架。
No man can do two things at once.
心无二用。
who is which depending on whether the customer's account is in credit or is overdrawn.
究竟谁是债务人谁是债权人，要看储户的账户是有结余还是透支。