My husband had just bought a new washing machine for me . I decided to use it the very day and I washed a lot of things .
Everything worked well , but I found one of my husband’s socks(短袜)  missing . I looked everywhere for it , but I couldn’t find it anywhere .
The next morning , I got ready for school as usual . When the bell rang , the students came in . I greeted them and told them what we were going to do that day .
When I turned around to write on the blackboard , the class burst into a roar (大笑声)! They laughed and laughed . They laughed so much , in fact ,that I was afraid the headmaster would come in to see all this .
I asked the class to stop , but the more I talked , the more they laughed . I decided to pay no attention to them and I continued to write on the blackboard . when I did this , they roared even more .
Finally , the teacher who had the room next to mine came in to see what all the laughter was about .
“Good heavens ,” I said , “Will someone please tell me what is so funny?”
“Oh , God,” said the teacher , “You have a brown sock to the back of your skirt !”
So that’s how I found my husband’s missing sock .
“Oh , well ,” I said to the class , “Let’s just say you have had an unforgettable lesson on static electricity(静电)。”
What was the writer ?

A．A washer

B．A student

C． A headmaster

D． A teacher

What happened when the writer turned around to write on the blackboard ?

A．The class roared with anger .

B．The class began to laugh loudly .

C．Another teacher came in

D．There was a loud noise outside the room

Why couldn’t she find one of her husband’s socks?

A．Because some students had hidden it .

B．Because her husband had taken it away .

C．Because she had left it in the classroom .

D．Because she never expected that it would stick to her skirt .

What did the writer do when she got to know why her students laughed?

A．She did nothing but laugh.

B．She got angry with the class .

C．She did nothing

D．She explained the matter in a clever way .