The Sanlu Milk Powder event is a clear indication that food safety is a big problem; nobody can ___ all foods are secure to us, but we are sure that the situation is turning for the better.
I couldn't imagine ______difficult it was for these badly injured victims to make it to the hospital.
—Where did you get this book? —I picked it up from a second-hand bookshop if you ______know.
—What are you two whispering about over there? —Oh, ______. Just small talk.
When I ______home, I caught a thief stealing from a passer-by.
The Charles Dickens Museum in Doughty Street is the only one of his London homes to survive, ______he wrote Oliver Twist.