The concept of the struggle for existence<span> concerns the competition or battle for resources needed to live. It can refer to human society, or to organisms in nature. The concept is ancient, and the term </span>struggle for existence<span> was in use by the end of the 18th century. From the 17th century onwards the concept was associated with a population exceeding resources.
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STSN</span>
I believe the mineral he found was mica.
The correct answer for the above question is the ejaculatory ducts. The male urethra is divided into three regions, one of them is the prostatic urethra which is the proximal portion that passes through the prostrate gland. It receives the ejaculatory duct, which contains sperm and secretions from the seminal vesicles, and numerous ducts from the prostrate glands.