Quiet: quiet to cultivate one's morality, frugality to cultivate one's morality or quiet can produce wisdom and will certainly produce wisdom.
Dull: dull and nihilistic, true spirit follows or aspires to be lofty, and interest is indifferent.
Germany: Germany is not alone, but it must have neighbors.
Xu: the mind is empty.
A lot. Everything is fine. Let's decide according to your situation. If you want to study, you should encourage yourself. To put it in the living room, you should use some inscriptions that make friends and have both ability and political integrity.