(1pt) What factors led to a major increase in agricultural productivity? more small farms
new machinery such as the seed drill
O
new seed types

2cool and cold temperature unless its an ever green tree 

Yeah, i guess that checks out because the unused brain is almost like a clean slate or a new car. it has more value than an older already used brain. -thomasnash

Airplanes usually fly in the lower part of the stratosphere - there is nearly no water vapor and it's very dry, so it to avoid big turbulences. it's about 8-10 kilometers above ground (depending on weather conditions, region etc.)

The ring off fire has most of the subduction zones in the world. these creates lots of volcanoes and earthquakes. hope this ! ; )