First, why do we get light propagating at all?首先, 我们来看看光为什么可以传播?The model shows a wave propagating from left to right through air.该模型表明,波从左至右通过空气.What are the pigeons doing outside? Eating, sleeping, propagating!门外的那些鸽子在...

v.捻成细粉，挑选( levigate的现在分词 )...

v.调查( investigate的现在分词 )，审查，侦查，研究...

conjugating的音标：...

"Mom," she intoned, elongating the word.“妈妈，”她拖长了声音，平静地说道。The torch can bring higher arc voltage with lower fluctuation by elongating the arc.该喷枪能够提高电弧电压并减小电弧电压波动.When upper internode elongating , sd - I was the most sen...

v.捆绑，束，综合( colligate的现在分词 )...

circumnavigating的音标：...