______I be free tomorrow,I could go with you.
I _________ here earlier, but I couldn’t catch the first bus.
--- Where did you find Lily?--- It is in the bookstore _________ she is working _________ I found her.
When _________ where he had put the book, he kept silent.
--- How often do you work out? --- _________, but usually once a week.
Vitamin C helps our bodies make a special chemical, which _______ affects our brains, making us feel happy.