The central focus point is more accurate/sensitive in many cameras, and so it is best to use this (instead of the outer focus points) — even if using it requires having to recompose afterwards.
All that carbon and oxygen — byproducts of the helium fusion process — build up in its core. At that point the star will shed its outer layers and the core will form a White Dwarf.
所有氦聚变中的附产物碳和氧在它的核心逐渐积聚,这期间它将失掉较外层物质,核心最终枯萎成为白矮星。
3
Most antibiotics directly attack the microbes that make us ill. Penicillin, for example, weakens bugs' tough outer wall to the point that many of them simply explode.