speedometer

Sometimes the instruments are read-only, like your speedometer.

有些仪器是只读的，就像速度计一样；

A population study from Finland has developed a fascinating scale that can predict 20-year risk for dementia –sort of a brain aging speedometer.

一项芬兰的人口学研究给出了一个引人注目的量表，能够预计20年罹患失忆症的风险，即一种大脑衰老的速度计。