Answer:
The first choice: 7,890 millimeters
Step-by-step explanation:
Remember that there are 100cm in a meter; there are 10mm in a centimeter.
100*10=1000
There are 1000 millimeters in a meter.
7.89*1000=7890
There are 7890 millimeters in 7.89 meters.
I hope this helps!!!
