The student did what they ___ the old man.
______ the workers’ working conditions, the boss will allow them to have a coffee break.
My friend David was not used _______ by air, so he felt unwell(不舒服).
We stopped on our way to London for _____.
____ that caused him to serve dinner an hour later than usual.
China ________ a sharp increase in the number of aged people over the past decade.