精选优质文档-倾情为你奉上中考英语选词填空20篇专心-专注-专业选词填空3before, discover , fast, in, come, watch , so, fast it, ago , shine, not can Light travels at a speed(速度) which is about a million times 1 . _ than that of sound. 2. _ one second, light travels about 300,000 kilometers, but sound travels only 340 meters. You can get some idea of this difference by 3. _ the start of a running match. If you stand far away from the starter(发令员), you can see smoke 4._ from his