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.

halogen, any of the six nonmetallic elements that constitute group 17 (group viia) of the periodic table. the halogen elements are fluorine (f), chlorine (cl), bromine (br), iodine (i), astatine (at), and tennessine (ts).

they deliver oxygen to the blood