As far as a threat, North Korea has been seen as such for many years (since WWII), when North Korea sided with Russia. America and its Capitalism were not fond of the Communist party, and so we have really been fighting/being concerned about Russian influence.
Historically North and South Korea have been in conflict many years before America and Russia got involved. When we did though it got worse.
Trump has done very little to resolve this, some would say he is making it worse.
AND as for any current events ask Google!
One astronomical unit is equal to the distance from Earth to the Sun. The second option among all the options given in the question is the correct option. The distance as calculated in the year 2012 by the International Astronomical Union was equal to 149597870700 meters. Astronomers like to use this unit for measuring the distances between planets and other solar bodies.
When ultraviolet light waves strike CFC molecules in the upper atmosphere, a carbon chlorine bond breaks, producing a chlorine atom. The chlorine atom then reacts with an ozone molecule breaking it apart and so destroying the ozone
The name of the region crossed by the trans-siberian railroad is SIBERIA or the WILD EAST. The eastern capital is Irkusk and the railroad passes through the city making it a stepping-off between Mongolia and China. The railroad goes through Siberia and China.
