滤线栅铅条会聚线到栅板的垂直距离称为
A、周长C
本题主要考查滤线栅方面知识。滤线栅铅条会聚线到栅板的垂直距离称为栅焦距，滤线栅栅比是铅条高度与铅条间距之比，栅密度是单位距离内的铅条数，没有栅距和周长的概念
Iappreciate________(give)theopportunitytostudyabroadthreeyearsago.
WhichofthefollowingstatementsisNOTtrueofEmilyDickinsonandherpoetry?
Wordsthatareidenticalonlyinspellingbutdifferentinsoundandmeaningarecalled______.
Alinguistictheoryisconstructedaboutwhat______isandhowitworks.
“Apple,pear,peach,orange,lemon,etc.”makeupthe______of“fruit”.
