Have you found any useful clues， sir？
We （work） on it． There's nothing much I can say at the moment．
Millions of young people （fight） in World War Ⅱ so we could live in peace．
Schools are still closed in some countries （stop） the spread of the virus．
Don't worry． Hobo is a smart dog and I'm sure he （come） back soon．
Anne Frank went into （hide） with her family and wrote the famous diary．