Read the given sentence. Identify the error and supply the correction in the sentence.
Ninety-seven percent of the Earth’s water is salty ocean water and another two percent is trapping in the Earth’s ice caps and glaciers. 
The verb “is trapping” is wrong; it suggests an ongoing action. Since the sentence describes a state, the correct passive form is “is trapped.”
Error: is trapping
Correction: is trapped
The passive form “is trapped” correctly shows the subject *receiving* the action.
This difference is key for clear, grammatically correct writing, particularly when describing states.
Always pick the verb form reflecting whether the action is active or passive within the sentence's context.