小明在载玻片上用细圆珠笔写了个字母“b”，然后放在显微镜下进行观察，那么它看到的图形应该是(    )

已知无穷等比数列{a_n}的公比为q，前n项和为S_n，且  $\underset{n\to \infty }{\lim }{S}_n$=S，下列条件中，使得2S_n＜S（n∈N^*）恒成立的是（　　）

假如你叫大明，收到了你的英国朋友Tony的来信，信中他很关心四川雅安地震后学生的情况。请你根据他的来信内容写一封回信，感谢他对灾区学生的关心，回答他的问题，并谈谈你的感受。
提示词语：thank you, care to， go on， government ，offer，encourage， brave　
Dear Daming,
I'm sorry to hear that a big earthquake happened in Ya'an, Sichuan. Some school buildings broke down in the earthquake and many students couldn't go to school. But I know the government is trying their best to help them. And Chinese people are so strong and brave that they aren’t afraid of anything difficult. Can the students go on studying now? Please tell me more about them.
I'm looking forward to hearing from you soon.
Yours, 
Tony
Dear Tony,
I'm glad to hear from you
Best wishes.  
Yours
Daming