He apologized for his mistake, saying that he ___________no offence.
When we climbed up to the top of the mountain, we were all ___________.
I wondered what difficulty he had _________ the plan?
My friend, David, was not used __________ by air, so he felt unwell.
The naughty boys would play ______trick on ______ neighbours who didn’t give them any sweets on Halloween.
Although he is very young, he is much more experienced than others _____ working ability.