Final answer:
Adiabatic cooling is true due to thermal expansion causing airmasses to cool when they rise and expand. The Coriolis force deflecting winds to the left in the southern hemisphere is also true, leading to the clockwise rotation of weather systems there.
Step-by-step explanation:
1. Adiabatic cooling of an airmass occurs by thermal expansion - True. When an airmass rises, the pressure decreases. The decrease in pressure allows the air to expand, and as it expands, it cools without exchanging heat with the environment, which is what we call adiabatic cooling.
2. The Coriolis Force deflects winds in the southern hemisphere to the left - True. The Coriolis force is a result of Earth's rotation and acts perpendicular to the motion of objects. This force causes winds to deflect to the left in the southern hemisphere, which leads to the clockwise rotation of weather systems like cyclones in that region.