Answer:
#1 is an organism
#2 is cell
#4 - Digestive System gets nutrients (good) from food and hands it over to the blood and Circulatory System then carries those nutrients where they need to go
Answer:

Explanation:
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In this case, since at 60 °C, 108 grams of ammonium bromide are completely dissolved in 100 grams of water for a saturated solution, once it is cooled to 30 °C, wherein only 83.2 grams are completely dissolved in 100 grams of water, the following mass will precipitate:

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Independent variable: the student chooses to miss class.
dependent variable: in result of the student missing class his grade goes down.
hyposthesis: if the student misses class multiple times, then his grades will go down.
Answer:
A
Explanation:
Element A has 3 electrons in outermost shell so its valency is 3. It will loose 3 electrons to attain stability, as loss of 3 electrons is easier than gain of 5 electrons.
Valency of B is −2 as it will gain 2 electrons to attain stability and combine with other atom.
Valency of A⟶+3
Valency of B⟶−2
(Refer to Image)
Cross multiply valency of A and B
∴A2B3 compound will be formed.