【简答题】如图所示,用射线理论分析子午光线在阶跃光纤中的传输原理。
【单选题】听力原文: when I first went to London as a student,I sat alone during parties with my glass of wine.I hoped people would think that I was having great thoughts and that someone might come up to me and say...
A.
Enjoyed the wine and delicious foods.
B.
Listened to the stories of friends.
C.
Sat alone and waited someone to come up.
D.
Talked to the interesting looking people.
【简答题】从方框中选出合适的句子补全对话。 A. What shows do you like? B. I think they are boring. C. What do you think of soap operas? D. My parents can't stand it. E. They are really interesting. A: Do you watch TV? B: Yes, ...