Which of the earth's spheres includes its mantle core and crust?

Afarmer who is grown corn for the past five years notices in the sixth year that the his harvest is significantly smaller, despite an increase in labor on the farm. the following year, the harvest continue to decline. which of the following explanations most plausibly accounts for the reduction in corn yield? a) soil degradation b) desalinization c) better irrigationd) terracing

True/false indicate whether the sentence or statement is true or false. southern africa experiences droughts and floods. select the best answer from the choices provided t f

In which layer of the atmosphere are the particles so far apart that they can travel hundreds of kilometers without colliding with each other? a.exosphere b.troposphere c.mesosphere d.thermosphere