Astudent made a model of isostasy by placing a block of wood in a beaker of water. what does the water in the beaker represent in the model? a. a glacier b. earth's crust c. earth's mantle d. a rebound

With i really need the correct answer!

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.

Which additional product balances the reaction h2so4 + 2naoh → na2so4 + 2h2o 2oh h2o2 h3o