Retention form
[医] 固位形(牙洞)
🧩 词语组成解析
retention
[ri'tenʃən]
n. 保留;记忆力，保持力;滞留，扣留;闭尿;
🗣️ 情景例句
Where are they?
草图在哪儿？
I wonder what happened to him.
我不知道他出什么事了。
Almost any day a young porpoise may be seen trying to turn a 300-pound sea turtle over by sticking his snout under the edge of his shell and pushing up for dear life.
几乎每天都可以看到一只小海豚把鼻子顶入一只300磅重的海龟的硬壳下面，拼命地把它翻过来。