John is a farmer who wants to keep his soil as productive as possible. Which of these actions would help him achieve this goal? A.
excessive irrigation
B.
crop rotation
C.
soil exhaustion
D.
leaching

How did the movement of soldiers during world war 1 contribute to the global influenza (flu) pandemic of 1918 to 1919, which killed millions of people

One of the brightest comets of the 20th century was comet hyakutake, which passed close to the sun in early 1996. the orbital period of this comet is estimated to be about 30,000 years. find the semi-major axis of this comet’s orbit. compare it to the average sun-pluto distance and to the distance to alpha centauri, the nearest star to the sun, which is 4.3 light-years distant.

Acontinental polar air mass foms in