Question

introduction
a floor jack is used to partially lift a vehicle from one end or the side. a relatively - small operating force is converted into a large lifting force. the floor jack transfers this force to the vehicle.
vehicles are heavy, so you should take care when lifting one. incorrect use of the floor jack can cause considerable damage to the vehicle. also, your safety (and that of others) may be put at risk.
why should you always be careful when jacking a vehicle?
your personal safety is put at risk.
the safety of others is put at risk.
the vehicle can be damaged if jacked incorrectly.

Explanation:

The text states that vehicles are heavy and incorrect use of a floor - jack can cause damage to the vehicle and put one's own and others' safety at risk.

Answer:

Your personal safety is put at risk.
The safety of others is put at risk.
The vehicle can be damaged if jacked incorrectly.