VOA慢速英语:Experts: North Korea Lacks Missile Technology to Reach Mainland US

intercontinental – adj. able to travel from one continent to another

ballistic missile – n. a weapon that is shot through the sky over a great distance and then falls to the ground and explodes.

altitude – n. the height of something above the level of the sea

astrophysicist – n. someone who studies the physical and chemical properties and structures of stars, planets, and other objects in outer space

milestone – n. an important point in the progress or development of something

second stage – n. the point at which a rocket disconnects from its main engines and fires secondary engines

steep – adj. rising or falling very sharply

angle – n. the position from which something is approached