Answer:
D
Explanation:
Letting dishes air dry reduces your use of energy, which usually comes from combustion, the process of burning fuels. This process releases carbon dioxide into the air.
'by hand' is a prepositional phrase which is functioning as an adverb phrase to explain HOW all books in Europe were once written.
Adverb phrases give additional details - like HOW something happens.
Soporific is an English word which means - cause to sleep. The origin of this word is Latin. It comes from the Latin word sopor - deep sleep.
