Food safety is important. Rules to stop people from food pollution.
— Jim, remember to return this book by Friday.— ________.
— Excuse me, can I interview Mr White?— A moment, please. Let me check ________.
If you watch carefully, you can see ________ the man does the trick with the cards.
Wars are disasters. A large number of people will lose their homes if a war ________.
The mobile phone has changed people’s life a lot ________ it was invented.