Big Ben, the landmark of London, a clock famous for its accuracy and chimes(和谐的钟声), stopped working for 90 minutes, an engineer said Saturday.
People do not know why the 147-year-old clock on the banks of the River Thames stopped at 10:07 p.m. Friday. It continued keeping time, but stopped again at 10:20 p.m. and remained silent for about 90 minutes before starting up again, a spokeswoman for the House of Commons said.
There has been speculation(推测) that a recent period of hot weather may have been to blame(责备). Temperatures in London reached 90 ℉on Saturday, and forecasters called it England’s hottest day in May since 1953.
The clock has experienced occasional problems. In 1962, snow caused the clock to stop before the New Year. In 1976, the clock stopped when a piece of its machinery broke. Big Ben also stopped on April 30, 1997, and once more three weeks later.
How many times has Big Ben stopped up to now?

A．Three

B．Five

C．Six

D．Eight

The probable reason for Big Ben stopping working this time is ________.

A．high temperature	B．low temperature
C．broken machine	D．heavy snow

The passage mainly talks about ________.

A．Big Ben’s history

B．the solution to Big Ben’s problem.

C．the landmark of London

D．Big Ben’s silence