Answer: 28000 milliliters.
Explanation:
First, we need to convert 7 liters to milliliters.
1 liter=1000 milliliters
So, 7 L=7x1000=7000 mL
Now we need to multiply to find the total amount of water. She refilled the watering can 4 times.
7000x4=28000
Li used 28000 milliliters of water in her garden all together.