Hello!
は？Choose:
It is thought that the pyramids of Egypt were built __ slaves and made __ with stone.
a. of
b. by
c. about
e. for
f. from
Answers:
The answers are b., ‘by‘ and a., ‘of’.
Explanation:
Things are made by people and of materials; so, pictures painted by Da Vinci were made of canvas, paint and oil. A house is built by a construction team is constructed of wood, cement, brick and mortar and tiles–or whatever. Many products are made of plastic by machines.
