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
This may sound like a dumb question, but I'd like to know.
这也许是个愚蠢的问题，但我想知道。
The problem is far from easy.
这问题绝非易事。
On the farm, everything begins to grow.The trees turn green, and the flowers start to come out.
农场里，各种作物开始生长。树木变绿，鲜花盛开。