Gap Filling Quiz

Fill in all the gaps by dragging the words in the top bar to their correct places.
Correct answers will appear in green and incorrect answers will appear in red.
lncorrect answers may be corrected by dragging the correct word to its place in the paragraph.
   bearings      braking      contact      force      freely      grip      heat      lubricants      slippery      useful   
Friction is a that tries to prevent objects from passing smoothly over each other.
It occurs where two objects are in .
Friction can prevent a car engine from moving .
It can also cause the moving parts to up.
That's why cars use such as oil, to help keep the parts moving freely.
To reduce friction, wheels are often mounted on ball , or oil is used to make moving parts more .
Friction can also be quite .
It allows shoes and tyres to the ground.
It is also useful in systems of cars and other forms of transport.