What pulls a roller coaster down a hill?
GRAVITY
The ........... ............. is my favorite attraction.
ROLLER COASTER
Don't forget to use the ................ bar.
SAFETY
He climbed the ............. hill by himself.
STEEP
This is a very .................. box.
HEAVY
The ................. of the car is incredible.
SPEED
Mandy is the girl ________ I met yesterday.
WHO
I saw a castle ________ was very beautiful.
WHICH
Gravity is a force. It pulls you down.
Gravity is a force which pulls you down.
