他怒视着她,却一言不发.He glared angrily at her but did not say a word.他一言不发地皱眉怒视我.He just glowered without speaking.他怒视着我，却一言不发。He glowered at me but said nothing....
通常的实验室光源选用汞弧灯.A common laboratory source of light is provided by a mercury arc.不很精确的射电干涉仪观测表明,这个源的角径约为1.5弧秒.Comparatively rudimentary interferometer observations suggested that this source is about 1.5 across.单个弧是不能求长的.T...