But of course, like any immutable system, there are mutable parts (otherwise, we couldn’t create any configuration files). OSTree handles this with “overlays” (actually, we use OverlayFS) that allow a read-write filesystem to be layered on top of the immutable system. For example, the /etc and /var directories are writable, while the rest of the system is read-only.
A device based on light-confining materials can modify superconductivity using quantum fluctuations, without the need for external illumination.
，这一点在91视频中也有详细论述
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第五十三条 纳税人实施不具有合理商业目的的安排而减少、免除、推迟缴纳增值税税款，或者提前退税、多退税款的，税务机关可以依照《中华人民共和国税收征收管理法》和有关行政法规的规定予以调整。