Read the following sentence from the section "The Satellites Layer."
But in the thermosphere, the
temperature can reach up to 4,500
degrees Fahrenheit.
What does the author mean by "up to 4,500
degrees"?
A
It cannot be any cooler than 4,500 degrees.
B
It has to always be at least 4,500 degrees or
hotter
С
It can get as hot as 4,500 degrees, but not
any hotter.
D
It is 4,500 degrees most of the time.

The body is protected against harmful flu viruses by

Slow down transpiration by the stomata question 9 options: a guard cells; closing b chloroplasts; closing c guard cells; opening d chloroplasts; opening

On a backpacking trip, kenny hikes all day at a steady pace, covering 30 kilometers and burning 4000 calories. at the school track, janelle runs the 100-meter sprint in 13.5 seconds, burning 10 calories. afterward, janelle’s leg muscles are aching and she is breathing hard, while kenny maintains normal breathing all day, even though he burns 400 times more calories than janelle. which two statements offer the best explanation for this phenomenon? a. if the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt." b. aerobic cellular respiration produces more energy, but its use is limited because of lactic acid buildup in the muscles and the resulting "oxygen debt." c. after about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce atp, resulting in "oxygen debt." d. the rate of energy demand determines how the muscles will obtain energy, either from cellular respiration or from lactic acid fermentation if not enough oxygen is present.