Focus on the pronunciation of lock
English definition of “lock”
/lɑk/ v [I/T] (NOT ALLOW CHANGE)
› to be or hold something in a position or condition where movement, escape, or change is not possible: [T] They’re locked in a lawsuit with their former employer. [I] The cars crashed and the bumpers locked, making it impossible to move. [M] The bank won’t lock in our mortgage rate.