In November 1998, a Chinese ocean-going ship "Changsheng" went to sea for three days and mysteriously disappeared. All communication was cut off and the lives of 23 Chinese sailors were unknown. Within 10 days, a large-scale search operation traveled all over the world from Southeast Asia to Greece to the United States, but the huge ship evaporated without a trace.In the "Learning Massive Open Online Course" section, free video courses are divided into 5 categories, including social law, science, technology, agriculture and medicine, humanities and philosophy, politics and economy, and others, totaling nearly 200 courses. This includes 16 social law courses such as "Operations Research", "Tort Liability Theory" and "Communication Psychology". "Diagnostics of Traditional Chinese Medicine", "Antenna Principle", "Astronomical Exploration" and other 63 science, technology, agriculture and medicine courses, "Nine Lectures on the Essence of Marxist Philosophy Principles", "Guan Zhong's Management Thought of Chinese Famous Phase" and "Five Types of Poetic Life" and other 60 kinds of human history and philosophy courses, 15 kinds of political and economic courses such as "CPC Tax System", "Political Ethics" and "Corporate Finance" and 24 kinds of other courses that have not yet been classified, such as "Self-shaping: Five Elements of Success", "Gem Processing Technology" and "Cosmetic Appreciation and Application".张槐等人都点头，说光听着就好吃。What is scarcity mentality? It is "the more scarce what is, the more you care about it."六十多艘战舰，数百门火炮尽皆在几息之间发射，场面极其壮观。There is a person who wants to learn English. He does not memorize words by rote, nor does he listen to English recordings hard.On Zhihu, a netizen said,
