HELP ASAP PLEASE I WILL MARK David roller skates 42 Km in 3 1/2 hours. What is his average speed in kilometers per hour? Speed =​

The zone, which exists from a depth of 0 to 600 feet, is home to the majority of ocean life.

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

Matthew decided he wanted to hike up mount everest. on his way to the top, it began to snow and the temperature dropped to -10°f. matthew forgot to wear a heavy jacket so his body began to shiver beyond control. in this case, matthew's body shivering is the to a drop in temperature. * 0 points reflex stimuli responce environmental facto