10.-Have you been to the Great Wall?-Perhaps not in my memory. _______ , it might have been during my early childhood.
The insect ______ a powerful drug which affects mosquitoes.
Believe it or not, there is ______ as standard English.
---Whose advice do you think I should take? ----______.
Is it the pigeon to______ he attached the message ______ carried the news there?
You are ______ to be hit by lightning ______be attacked by a shark, so don’t be frightened by sharks.