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.
You must cut off one pound of flesh, no more, no less. And not one drop of blood must fall.
你必须割下整一磅肉,不准多也不准少。而且不准流一滴血。
For example, you might pick up a travel book and read a few pages before going to sleep. It is enough to dip into it and read bits here and there. In a word, this is tasting.