I find it astonishing that he ____ be so rudeto us I _____ make a complaint to his company

It has been announced that candidates _____ remain in their seats until all the papers have been collected.

Yesterday, I came across my former classmate, but his name ________ me, which made me embarrassed

See you next Friday— Next Friday? Why, what ________ that day?

______ proves that Jack is really enthusiastic and cautious.