Select the items from the following list that can be classified as a current liability, non-current liabilities, a provision or a contingent liability.

• Accounts payable
• Unearned revenue
• Accrued revenues
• Accrued expenses
• Provision for warranty repair costs (1 year)
• 20 - year debentures
• Mortgage payable (30 years)
• Accumulated depreciation
• Allowance for doubtful debts
• Income tax payable
• An unresolved lawsuit against the entity for copyright infringement
• Environment damage that an entity has undertaken to repair