Television has many advantages．It keeps us ____ of the latest news and also provides entertainment in the house．_______ it’s so popular worldwide.

A．informed, No wonder

B．to know, No doubt

C．learning, No chance

D．to think, No problem

对数分布用于（）引起的失效分布。

A.裂痕扩展

B.磨损寿命

C.疲劳失效

D.同一批晶体管放大倍数的波动或寿命波动