What time will the star Canis Major set on December 30 this year? (Give your answer as if you are a Sacramento observer.)

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.

The ph is the a.independent variable b.the dependent variable c.control group

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.