Clouds are formed when a. sunlight causes water droplets to evaporate b. liquid water condenses on grass and windows c. raindrops freeze into tiny pellets and fall to earth d. water vapor in the air condenses to form liquid water or ice

Clouds are formed when;

D. Water vapor in the air condenses to form liquid water or ice

Clouds form when warm and moist air rise and expands in the atmosphere. Water vapor condenses  into small pieces of dust, which later conjoins to form a cloud.

dang you just copied and pasted

explanation:

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation: