Examlex
About what percentage of the mass of a molecular cloud is in the form of dust?
Just Say No
An anti-drug campaign promoted in the 1980s by US First Lady Nancy Reagan, encouraging youth to resist peer pressure by simply saying "no" to drugs.
Tax Rate
The percentage at which an individual or corporation is taxed on their income or profits.
Strategic Defense Initiative
was a proposed missile defense system announced by President Ronald Reagan in 1983, intended to protect the United States from attack by ballistic strategic nuclear weapons.
Anti-Ballistic Missile Treaty
A treaty between the United States and the Soviet Union on the limitation of the anti-ballistic missile (ABM) systems used in defending areas against missile-delivered nuclear weapons (1972-2002).
Q3: No visible light can escape a black
Q30: The quantity called the "enclosed mass" M(<r)represents
Q33: The sketch above shows groups of stars
Q71: How do we determine the amount of
Q76: The flat rotation curves of spiral galaxies
Q89: Current estimates place the age of the
Q93: Briefly describe two different ways of measuring
Q106: From an observational standpoint, what is a
Q107: A lenticular galaxy is another name for
Q120: Reflection nebula are bluer than the stars