Retention aid
[化] 助留剂
🧩 词语组成解析
retention
[ri'tenʃən]
n. 保留;记忆力，保持力;滞留，扣留;闭尿;
aid
[eid]
n. 帮助;助手;外援;辅助设备;
vt. 帮助;资助;救助;促进;
vi. 帮助;
🗣️ 情景例句
Claims, if any, must be made within 30 days after the arrival of the goods.
索赔必须在货物抵达目的地后30天内提出。
Long looked for comes at last.
久久寻找，终会找到。
What do you find hardest in English?
你觉得学习英语哪方面最难？