Some of these cities are popular with companies who want to open new offices near Cairo and want their workers to live in comfortable conditions.
هذه الجملة موجودة فى ٌReview B (Reading text)
فهل وجود who فى هذه الجملة صحيح و لماذا

فعلا الجملة موجودة فى Review B
اعتقد انها المفروض Which وليست who

That's true.I have read that.

But I think in my opinion that companies here meant the owners of the companies as company refers to a group of people who works in a specific( certain) place

نريد مشاركة الجميع حتى تعم الفائدة و نصل لحل مرضى

ممكن كلمة companies هنا تكون بمعنى صحبة او رفقة او جماعة

السلام عليكم ممكن حل هذا السؤال:
He couldn`t answer the questions correctly because he hadn`t studied hard. ( Had)

Had he studied hard, he could have answered the questions correctly

المقصود ب companies هنا الصحبة او الاصحاب ولذلك يمكن وصفها بwho

الجملة صحيحة 100% لان كلمة company تعريفها كالتالى:
Company : a group of people who work together professionally or for a common purpose
و تاتى أيضا بمعنى موسسة ايضا و لكن اعتقد لان الفعل بعد who هو want فاعتبرت عاقل بالمعنى الاول للكلمة