The development of industry has been ______ gradual process throughout ______ human existence, from stone tools to modern technology.
Every minute is made full use of _________ our lessons before the exam.
Help is needed for families _________ homes were destroyed during the earthquake.
Adam behaved _________ he had never heard such a thing before.
Jason has lost his job and is now _________ a very difficult time.
— Thank you so much for the lovely evening, Jim.— _________.