The development of industry has been _____ gradual process throughout _____ human existence, from stone tools to modern technology.
---- Could I borrow your bike? ---- I’m afraid you _______.
---- Thank you for your help. ---- ________.
----- Sorry to have hurt you. ----- _______. You didn’t mean to, did you?
---- He seldom goes abroad, does he? ---- ________. Only once when he was young.
---- Waiter! ----_________ ----What’s in the soup? Is it a fly?