—Are you free tomorrow afternoon?—I'm afraid not. I'll have to ________ an important lecture given by a famous professor.
He is so busy.He cannot afford enough time with his son________he wants to.
I have heard a lot of good things about you ________ I came back from abroad.
________I have to give a speech,I get extremely nervous before I start.
Mark needs to learn Chinese________his company is opening a branch in Beijing.
One can always manage to do more things,no matter________full one's schedule is in life.