The professor devoted all his life ____the treatment of AIDS.A to research B.in researching C.to researching D.at researching
Much to my , I’m unable to accept your kind invitation.
—Shall we hang out tomorrow morning? — ________ I’ll save the morning for my essay.
-- Isn’t that Ann’s husband over there?-- No, it ________ be him. I’m sure he doesn’t wear glasses.
I didn’t believe the reasons he explained _____ me.
He is difficult ________.