First-day cover
n. 首日封
📖 牛津释义
first-day cover
envelope with a set of special stamps postmarked on the first day of issue 首日封.
🧩 词语组成解析
first
[fɝst]
n. 第一，最初;头等;一号，;[乐]高音部;
adv. 最早，最初;首次;宁愿;优先;
adj. 第一流的;最初的，最早的;基本的，概要的;高音的;
num. 第一;
day
[de]
n. 一天;白天;时期;节日;
adj. 日间的;逐日的;
adv. 每天;经常在白天地;
🗣️ 情景例句
I had a million things to do today.
我今天有成千上万的事要做。
I think it's going to take at least 2 days.
我认为它将花至少两天时间。
In all the less controversial fields, like the study of cacti or termites or the nature of nebulae,
在一切争议较小的领域里，如对仙人掌、白蚁或星云性质的研究，