In order to improve your spoken English, you ________ be afraid of losing face. 

---Is the girl in the red skirt your sister?---No. It _______ be her. She has flown to Australia.

---- It’s the office! So you _____ know eating is not allowed here.---- Oh, sorry.

I ______ tell you with certainty that he won’t be able to finish it before the deadline. 

—Everyone in my class passed the exam.—Oh, really? It ________ difficult.