প্রশ্ন: A major concern among archaeologists today is the preservation of archaeological site, ____ are threatened by development.
(ক) of which many
(খ) many of which
(গ) many of them
(ঘ) of which many
ব্যাখ্যা:
Relative clause এ ‘many of which’ ব্যবহার হয়। Rule: quantity + of + which.