Physical properties of tungsten

Tungsten is a rare precious metal, since 1783 was discovered scientists, has been 200 years of history. According to estimates, the content of tungsten in the earth's crust is one in a million. China's tungsten reserves account for about 60% of the w.......

Ford with printing function

Ford with printing function_double-row vaccine transporter_new crown vaccine delivery vaccination vehicle bidding_price_new Transit vaccine cold chain truck is cheap What kind of new crown vaccine is currently used? Dosage and interval.......

Dust harm to the human body

Dust is harmful to the human body in many ways. The nasal cavity is a good dust filter for humans. Generally, dust particles larger than 10 microns are trapped in the mucus layer of the nasal cavity and upper respiratory tract under the action of gravity and inertial collisio.......