The ratio of primary care doctors to population is higher in Massachusetts than in other states.
在马萨诸塞州，初级保健医生与总人口比例高于其他各州。
2
Engine pressure ratio (EPR), the ratio of inlet pressure over exhaust-let pressure measurements. The ratio is used as the primary parameter to set thrust on some engines.
发动机压力比(epr)，进气压力与排气压力值的比，某些发动机以此作为设定推力的主要依据。
3
The test shows that size distribution of feeding coal, volatile content and its release as well as the total air rate and primary air ratio will influence the post combustion in CFB boiler.