the first time; for the first time; first

Occurring only once; one-off

linear equation; a mathematical equation of the first degree

A mathematical function that can be graphed as a straight line.

an algebraic equation of the first degree, in which the highest power of any variable is one

to become familiar with something or someone after repeated exposure; strangers at first meeting soon become friends

Energy source found in nature that has not been subjected to any conversion or transformation process

To learn from a mistake or experience; to take something as a lesson for the next time.

on more than one occasion; many times

once more; again

yet again; once more; yet another time

on one occasion; once upon a time

each time; every single time

once every week; occurring on a weekly basis

The global conflict that lasted from 1914 to 1918; often shortened to [[一战|一戰|yi1 zhan4]].

World War I (1914-1918)

this occasion or occurrence

over and over again; time after time

single-use cup typically made of paper or plastic used for drinking and discarded after use

Chopsticks made of wood or bamboo designed to be used once and then thrown away; often called [[卫生筷|衛生筷|wei4 sheng1 kuai4]]. In Taiwan, also known as [[免洗筷|免洗筷|mian3 xi3 kuai4]].

a single payment that settles an entire debt or amount due; lump-sum payment in finance