[請益] TPO 18 Lighting最後一題

看板TOEFL_iBT (TOEFL_iBT托福)作者peter3752001 (陽光啦啦佑)時間14年前 (2011/10/14 00:49)推噓2(2推 0噓 1→)

留言3則, 3人參與討論串1/1

各位版大又是我... 想請教 TPO 18最後一題(版上只討論第4選項) Most lightning takes place within a cloud when the charge separation within the cloud collapses. However, as the storm cloud develops, the ground beneath the cloud becomes positively charged and lightning can take place in the form of an electrical discharge between the negative charge of the cloud and the positively charged ground. Lightning that strikes the ground is the most likely to be destructive, so even though it represents only 20 percent of all lightning, it has received a lot of scientific attention. ○1.A storm cloud first develops a positively charged layer at the top then a negatively charged middle layer and finally, a positively charged layer at the bottom. ○2.Lightning from cloud to ground follows a channel that forms when a stream of electrons moving down meets a stream of positive particles coming up from the ground. ○3.Lightning from a cloud to the ground is more likely to be destructive than is lightning that takes place within a cloud. ○4.A separation of oppositely charged particles in clouds develops from collisions of falling ice pellets with ice crystals, from updrafts and from temperature variations. ○5.Field studies laboratory simulations and high-speed photography have all been used to investigate the way charge separations develop in clouds. ○6.Once a channel has been formed it is usually used by several successive electrical discharges that illuminate the channel as flashes of lightning. 我手邊的答案是 2,4,6 想請教的是3不能選的原因是不是因為原文說是the most likely而選項則說是more likely? 謝謝版大們 -- ※ 發信站 :批踢踢實業坊(ptt.cc) ◆ From: 140.112.230.149