Fire Station No．6 in Livermore，California，houses a celebrity—a 107-year-old light bulb(灯泡)that has been on for over a million hours，earning the title of the“World’s longest continuously burning bulb”by Ripley’s Believe It Or Not!The bulb also holds the Guinness World Record．
Nobody knows why this bulb has stayed alive for so many years．Most people believe that it is due to two reasons—it has almost never been turned off and it is really well made．Its perfect seal lets no air in．keeping its carbon filament(灯丝)from burning out．
The bulb was first installed at the fire department hose cart house on L Street in 1901．In 1903 it was moved to the new Station 1 on First and McLeod，and survived the renovation(翻修)of the Firehouse in 1937．when it was off for about a week．The last time the bulb was switched off was in July l976，when it was moved to Fire Station No．6．Thousands of people watched as the electrician tried to re-attach the bulb at its new location．At first nothing happened and people thought the bulb had finally died．However，a slight touch of its switch and then，the bulb came on and has been on since．Nobody at the station dares to touch it，even to clean it．
A local reporter first discovered the bulb’s significance in 1972．He recommended his readers to go visit it if they ever went to Livermore．All of a sudden thousands of people came to Fire Station No．6 and the bulb became famous．
Needless to say，the bulb is now a big source of pride and joy for the city of Livermore．So when some folks offered to buy it，the answer from the city was“NO!”
Which of the following may not be a reason for the bulb to stay alive for so long?

A．It was seldom switched off.

B．It was made of high quality．

C．Its carbon filament was special．

D．Its seal was perfect．

What does Paragraph 3 mainly talk about?

A．The brief history of the bulb．

B．The problems with the bulb．

C．The main function of the bulb．

D．The location where the bulb is．

We can learn from the text that the bulb _______________．

A．will eventually be owned by Ripley’s Believe It Or Not

B．is now becoming a proud symbol of the locals in livermore

C．has never been touched or cleaned in Fire Station No．6

D．wouldn’t have been discovered without the local reporter