No.1
Another was the oldest child.
Still another was the youngest child.

The word
yet functions sometimes as an adverb and has several meanings: in addition ("yet another cause of trouble" or "a simple yet noble woman"), even ("yet more expensive"), still ("he is yet a novice"), eventually ("they may yet win"), and so soon as now ("he's not here yet"). It also functions as a coordinating conjunction meaning something like "nevertheless" or "but."
Source
Do you mean 'still' is the only choice?
In colloquial spoken English, mind you, but still or still are sometimes used as less formal alternatives to yet:- The weather was lousy. It rained every day. Still, we managed to enjoy ourselves.
- I don’t like the work very much. Mind you, the people I work with are very nice.
- You can be very annoying at times, but we still love you.
Source No.2
Other materials are used in the workshop also,
about which some details will be given.
–preposition 1.of; concerning; in regard to:
instructions about the work; a book about the Civil War.
Could you please tell me if
–preposition refers 'about' ? And do you think aobut is correct? Could you please tell me if 'of' is correct here?
No.3
They are people
against whom we measure others.

-
measure against means to compare
-
measure with means to use as a tool
There is an example in my dictionary: measure one's strength with ( or against) another's.
That's why I felt confused. Could you please kindly explain that?
Looking forward to hearing from you.
Thank you in advance.
Jiang
Hope that helps.
