When a toy flashlight does not work, which two parts should you check and how are the parts related?

When a toy flashlight does not work, which two parts should you check and how are the parts related? My homework; Predicting, communicating example: Your little sister tries to turn a toy flashlight on one evening, but it does not work. Which two parts shoudl you check? How are the parts related?Handheld Flashlightled flashlight rechargeablesurefire led