Radioactive standard
[化] 放射性標準源
?? 詞語組成解析
standard
['st?nd?d]
n. 標準，規格;旗，軍旗;度量衡標準;直立支柱;
adj. 標準的，合格的;普遍的，一般的;公認為優秀的;
??? 情景例句
Aren't you going to the aerobics class this morning?
今天上午你不是去上有氧運動課嗎？
All of those houses have been built in the last ten years.
所有那些房子在這10年里被造的。
Even though the road was littered with boulders and pitted with holes, Bruce was not in the least perturbed.
盡管路面布滿石頭，坑坑洼洼，但布魯斯卻一點兒不慌亂。