Part of a company's draft statement of cash flows is shown below: $'000Net profit before tax 8,640Depreciation charges (2,160)Proceeds of sale of non-current assets 360Increase in inventory (330)Increase in accounts payable 440The following criticisms of the above extract have been made:1Depreciation charges should have been added, not deducted.2Increase in inventory should have been added, not deducted.3Increase in accounts payable should have been deducted, not added.4Proceeds of sale of non-current assets should not appear in this part of the statement of cash flows.Which of these criticisms are valid?