在生活、生产和科研中,经常要进行长度和时间的测量．要进行测量,就要有一个公认的测量标准,即测量单位．在国际单位制中,长度的单位是米(m),时间的单位是秒(s)．一般情况下,测量长度和时间要用适当的测量工具,还要掌握一些测量方法． In life, production, and scientific research, length and time are often measured. To make a measurement, there must be a recognized measurement standard, the unit of measurement. In the International System of Units, the unit of length is meters (m), and the unit of time is seconds (s). In general, measuring length and time must use appropriate measurement tools, but also some measurement methods.