Microsoft ended support for Windows XP after April 8, which _______a major operating system for some Chinese computer users, and advised users to upgrade to Windows 8.1.
John seemed puzzled about _____ the question meant.
Everyone tells me I’m a good speaker, _____ I really don’t like speaking in public.
—You've got a cold, not the H7N9! Everything will turn out OK. —______! I have been worrying about it for days.
Mike apologized for _______ to inform her of the change in the working plan.
It was Tom as well as two of his classmates that _______ invited to the party.