Usually congress passed the laws but it took 9 out of 13 states to ratify for a convention of states
By the given statement in question, Truman wanted to imply that the effect of communism was growing and if it could not be checked by aiding such countries as Greece and Turkey, then it would have far reaching effects. Truman feared that communism would slowly grip these countries in financial trouble and spread to the Latin American countries and the countries in the East at a very fast rate.
Well at first people named things for how they looked, for example, the heart has a heartlike shape. Eventually scientists started using Greek and Latin roots and such in names to prevent confusion.
D.
All of these were problems the Roman Empire was facing in the late second and third centuries.