问题
填空题
实验告诉我们,______的电流能够产生电磁波;电磁波在______中传播速度最快,是______m/s.
答案
迅速变化的电流周围产生电磁波,且电磁波在真空中的传播速度和光速相等,都是3×108m/s.
故答案为:迅速变化;真空;3×108.
实验告诉我们,______的电流能够产生电磁波;电磁波在______中传播速度最快,是______m/s.
迅速变化的电流周围产生电磁波,且电磁波在真空中的传播速度和光速相等,都是3×108m/s.
故答案为:迅速变化;真空;3×108.
A. Weather Report B. China 2001 C. Around the World D. Animal World ( )2. If you are a basketball fan, you may watch TV at ______________ . A.19:00 on Channel 2 B. 19:40 on Channel 1 C. 20:20 on Channel 2 D. 21:15 on Channel 1 ( )3. How long does the TV play “A Big Family” last? A.30 minutes B. 50 minutes C. 90 minutes D. 100 minutes ( )4. You can watch ______________ if you want to learn English on TV. A. English News B. English Classroom C. English for Today D. all the above ( )5. You should wait until _______ if you want to know the programs of next week. A.21:55 B. 22:05 C. 21:00 D. 21:45 |