Question

use the text to compare and contrast low pressure systems and high pressure systems.
watch a weather report, and youll probably hear the meteorologist talk about pressure systems. a low pressure system develops when air becomes hot and moist compared to the surrounding air. as the hot air expands, it rises upward, where it cools. a high pressure system is different in that air from higher in the atmosphere sinks down. this sinking air prevents warm air from rising, so the atmosphere is stabilized. high pressure systems bring dry, sunny weather. in the case of low pressure systems, the rising air cools to the point that clouds form, and rain or snow may fall. how do meteorologists know which pressure system is present? they detect low and high pressure systems by measuring air pressure with electronic sensors.

Explanation:

• For "Occur when air sinks down": The text says high - pressure systems occur when air sinks down. So, this is for high - pressure systems.
• For "Cause clouds to form": The text states that in low - pressure systems, the rising air cools to the point that clouds form. So, this is for low - pressure systems.
• For "Are detected by electronic sensors": The text mentions that meteorologists detect both low and high - pressure systems by measuring air pressure with electronic sensors.

Answer:

• Occur when air sinks down: High pressure systems
• Cause clouds to form: Low pressure systems
• Are detected by electronic sensors: Low pressure systems, High pressure systems