You could be depressed from a lot of different things, from losing your job to someone passing away
In a cactus, carbon is fixed only during the day. this is because cacti need sunlight to perform photosynthesis. Have a great day :)
Of its valence electrons or the no. Of valences in its Valence shell .In case of noble gases, their outermost shell is absolutely crammed so no emptiness is available in the outer maximum shell. Thus the oxidation kingdom is 0(zero)for Noble gases. Because, they've complete electrons in their out maximum shell.
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2 is B. Water freezes and 4 is the rock breaks.
I think the answer is Phenylketonuria.