n North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776
n a base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine
n a heavy toxic silvery-white radioactive metallic element; occurs in many isotopes; used for nuclear fuels and nuclear weapons
n the 21st letter of the Roman alphabet
pron. 我们
[经] 美国