Service ceiling
实用升限
🧩 词语组成解析
service
['sɝvɪs]
n. 服务，服侍;服务业;维修服务;服役;
vt. 检修，维修;向…提供服务;保养;满足需要;
adj. 服务性的;耐用的;服现役的;
serv服务+ice表名词，行为，状态 →服务
🗣️ 情景例句
Hi, there!
你好！
It's a hard job, but I hope he can make it.
这不是件容易的差事，但我希望他能做到。
is as the proportion of the total vocabulary of his mother tongue against those words of his own baby talk that are taken up into the vernacular of his family.
就好像他本国语言的总词汇量和自己咿呀学语时他家庭所接纳的他的词汇量之比。