Op Amp: What are two advantages of using 4-20 mA loops in real-life applications

This is for a final exam review. My textbook does not have a chapter on Op Amps so I cannot look it up.

I am aware of one: Long leads can be run to one central location that displays our desired info.

Anything would help, thanks!

Here are some of the reasons a 4-20 mA current loop is used.
1. You can detect if the sensor becomes disconnected. This may be very important in some applications.
2. It avoids trouble with ground loops or a shift in ground potential between the sensor and the circuit it is driving.
3. It has better noise rejection.