Directions:
You were supposed to attend a conference yesterday but for some reason you could not go and failed to ask for leave of absence. Write a letter to John Smith, the manager of your company, explaining why and apologizing for your negligence of duty.
Do not sign your own name. Sign "Wang Zhen" instead.

A．is fairly optimistic about the economic recovery.
B．sold his products well in the first half of the year.
C．never knows when his business will stop making a profit.
D．is very cautious about the present economic situation.