---Have you returned the book to the library _______?---Yes, I have _______ retuned it.
There ______ something wrong with my bike today, so I have to walk to school.
--When will Mr. Black come to Beijing? --________ the morning of September 5th.
--Who’s your Chinese teacher? --Miss Zhang. She has taught ______ Chinese for two years.
Jenny will visit me if he ____________ here.
We have happiness, ____________ still we have trouble sometimes. That’s life.