科学家使用精密计时器来测量化学反应的时间。

Scientists use a ___chronograph to measure the duration of chemical reactions.

他的新款计时码表可以精确测量短跑时间。

His new ___chronograph can accurately measure sprint times.

科学家使用精密计时器来测量火箭发射的时间间隔。

Scientists use a high-precision ___chronograph to measure the time intervals of rocket launches.