Trace constituent
[化] 痕量成分
🧩 词语组成解析
trace
[tres]
vt. 跟踪，追踪;追溯，探索;探索;查找;
vi. 沿着一小径或道路前进;可以追溯的;
n. 痕迹，踪迹;微量，极少量;[植]（脉）迹;痕迹;
trace(draw)→回溯
🗣️ 情景例句
for the one seat on the Riverdale School Board,
争夺Riverdale联合校董会一个席次
There are seven of us altogether.
一共有7个。
Hello, Bruce. What a beautiful day!
你好，布鲁斯。天气多么好啊！