Which information does the outer ring of a compass rose on a nautical chart provide（）. ["variation","true directions","magnetic directions","annual rate of variation change"]
A spring-loaded centrifugal flyweight governor responds to reduced engine load with an immediate increase in （） ["pilot valve oil pressure","speeder spring force","compensation needle valve clearance","centrifugal force on the flyweight"]
螺旋电流过大的原因？
一个N位逐次逼近型A/D转换器完成一次转换要进行N次比较，需要N+2个时钟脉冲。
胎儿必须从母体中获得营养和氧气。胎儿的血红蛋白分子与成体的血红蛋白分子略有不同。据此推断这种不同最可能导致（） ["胎儿血红蛋白与氧的亲和力更强","胎儿血红蛋白合成步骤更简单","胎儿血红蛋白功能更多","胎儿血红蛋白更易发生变异"]
搅拌跳停的原因有哪些？
