swarm n. 1.(昆虫的)群,蜂群;【生物学】浮游单细胞(生物)群,游走孢子。 2.大群;大堆。 a swarm of sightseers 大群游客。 a swarm of letters 一大堆信。 in swarms =in a swarm 成群;大批。 vi. 1.蜂拥成群(而去);(蜜蜂)成群离巢,分群;【生物学】(细胞等)成群裂出[浮游]。 2.密集;群集;被挤满;充满。 3.攀缘,攀登。 The garden swarms with bees. 花园里有许多蜜蜂飞来飞去。 The mosquitoes swarmed about us. 蚊子成群地环绕着我们。 People swarmed into the cinema. 人们蜂拥而进入电影院。 The swamp swarms with mosquitoes and other insects. 沼泽地到处都有蚊子和小昆虫。 vt. 1.攀缘。 2.挤满。 swarm (up) a rope 攀缘绳索。 be swarmed with (rats) 充满着(老鼠)。 -ing 【虫类】婚飞;分群;群游。 vi.,vt. (抱着)爬(树等)。
This at least accounts for the fact that a particular group of meteoroids shares with its parent comet more or less the same orbit , which can remain relatively unchanged over eons . an immediate consequence is that our earth makes periodic rendezvous with this meteoroid swarm , thereby culminating in a regular display of these celestial fireworks . to name a few , we have the lyrids in april and the geminids in december 流星雨的成因是地球遇上了一群密集的流星体,一般相信,流星群是由周期性彗星分解出来的物质或由瓦解了的彗核所形成,所以流星群和其母体彗星有大致相同的轨道,由于流星群的轨道颇为固定,所以地球会周期性地穿越这些流星群,形成固定出现的流星雨,例如四月天琴座流星雨十二月双子座流星雨等。