proficiency
n[U]
~ (in sth/doing sth)being proficient (in sth) 精通; 熟练
a test of proficiency (in English) (英语)水平测试
show proficiency in operating a switchboard 操作配电板十分熟练.
The Native Americans caught and trained them and were then able to use them to carry their goods when they travelled from one camping ground to another.
美洲土著人捕捉野马,加以驯服。
In the evenings he studied hard for his exams, and most mornings he took tourists around Oxford.