Explanation:
Roughly one out of every thousand stars that form is massive enough to become a black hole. Therefore, our galaxy must harbor some 100 million stellar-mass black holes. Most of these are invisible to us, and only about a dozen have been identified. The nearest one is some 1,600 lightyears from Earth.
-Pencils were first used in 1662.
-Graphite is a crystalline form of the element carbon with its atoms arranged in a hexagonal structure.
- HB is a graphite hardness/grading scale: the higher the number next to H, the harder and lighter/less dark the pencil lead is.
- The H stands for “hard.”
Answer:
the answer is C.
Explanation: That is the answer, because we have to put a filter over it so we don't breath poisonous air.
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Max Weber believed that the study of society should involve social activism.