解释这两句关于as as 的用法

i am sure he is not such a man as (这个是定语从句的引导词可以替换成who)would leave his work half done

as 这个表示原因many instruments （as are in the lab ）括起来的部分是个定语从句，修饰instruments,千万要理解成as...as结构。have been made most use of

希望你看明白了

such sth as下述一类的; （像后面提及的）那样的, 这样的, 如此的
Such a disaster as her car being stolen had never happened before.
有的祸事, 像她的汽车被盗之类, 以前从未发生过.

as...as
达到与...相同的程度; 与...等同
as tall as his father 和他父亲一样高 * This dress is twice as expensive as that. 这件连衣裙比那件贵一倍. * He doesn't play half as well as his sister. 他演奏的水平不及他姐姐的一半.

as...as...中的第一个as是副词， 后接形容词或副词的原级， 或接形容词再接名词；第二个as是连词，后接从句
例如
She is as tall as I.
She writes as carefully as I.
She has as many books as I.

i am sure he is not such a man as would leave his work half done
such +名词+as 这是一个定语从句，我确信他不是一个会半途而废的那种人。
as many instruments as are in the lab have been made most use of
as+名词+as也是一个定语从句，试验室里有很多的器材被成分利用。