带电粒子通过物质时,与物质的主要直接作用是()。
A、直接电离ABC
暂无解析
We______togotothesupermarketbecausewehadplentyoffood.
Idon’tneedanyhelpatthemoment,butI_____youroffer
单色光垂直入射到每毫米500条刻痕的光栅上.若入射光波长为5.0×10-7m,求第二级主极大的衍射角;
Thegroupismadeupoflocal___(music)whohavebeenperformingtogetherforseveralyears.
Weknewtheboss________beangryifwedidn’tfinishtheworkintime.