You should check the security guideboard if you want to （ ）.
举一反三
- You should check ( ) if you want to visit ( .).
- You should check ( ) if you want to learn about ( ).
- When you go through the security check, if you have a laptop in your bag, you should take it out and put it in a tray.
- what objects should be taken out to be checked when you go through security check ？
- If you want to check in at the hotel, you need help from _____.