Some seismometers are capable of detecting ground motion as small as 1 billionth of a meter,or about 40 billionth of an inch. 一些地震检波器能探测相当于十亿分之一米或亿分之四英寸的地面运动。
billionth英英释义
Noun:
position 1,000,000,000 in a countable series of things
one part in a billion equal parts
Adjective:
the ordinal number of one billion in counting order
