Write a query to show only those Invoices that have not been paid. There are multiple ways to do this- it depends on how you determine that the Invoices are unpaid. Show only columns that are relevant to the query.

1. which of these is not true about torsion bars? a. they can be used to adjust ride height b. they can be adjusted anytime since they don't affect alignment angles c. they attach between the frame and the lower control arm d. they twist to produce a spring effect