Half-value layer
[医] 半值层, 半价厚度
🧩 词语组成解析
half
[hæf]
adj. 一半的，半个的;
n. 半;一半;（啤酒等饮料的）半品脱;（比赛、音乐会等的）半场;
adv. 一半;部份地;
layer
['leiə]
n. 层，层次;膜;[植]压条;放置者，计划者;
vt. 把…分层堆放;借助压条法;生根繁殖;将（头发）剪成不同层次;
vi. 形成或分成层次;[植]通过压条法而生根;
🗣️ 情景例句
Sure.
当然。
He knows most who speaks least.
大智者寡于言。
Up to now, historians have assumed that calendars came into being with the advent of agriculture, for then man was faced with a real need to understand something about the seasons.
历史学家迄今认为日历是随农业的问世而出现的，因为当时人们面临着了解四季的实际需要，