What 4 things MUST be present in order for a disease to be transmitted?

Air can be considered a mixture. which statement does not explain why?

27 drag each label to the correct location on the image. a particular exosolar system has five planets in total: a, b, c, d, and e. the table lists the orbital periods of these planets in days. planet orbital period (days) a 600 b 80 c 1,000 d 500 e 100 move each planet to its orbit in the system.

2ki + pb(no3)2 → 2kno3 + pbi2 determine how many moles of kno3 are created if 0.03 moles of ki are completely consumed.