4 Open the brackets using the verbs in the correct voice
forms:
(1) Precious metals (use, are used) for various purposes.
(2) They can (use, be used) as any other commodity.
(3) They can (buy, be bought).
( 4) People (use, are used) them for jewellery industry.
(5) We also (use, are used) them for electronics, dentistry and other
industries.
(6) They (use, are used) for minting coins.
(7) We also (use, are used) them for medals.