國中英語基測出現過 a 的考題。

One evening, my dad asked me to buy some bread for dinner. It was dark and cold outside. I rode a bike to a store near my school. When I left the store, it got even darker, so I got on my bike right away. Then I found a woman in a white dress riding a motorcycle after me. She followed me for a long time. I rode very fast and started to cry for help, but no one was there. I was too scared and too tired to ride any faster. At last, I gave up. The woman stopped in front of me and said, "Why were you riding so fast, Ken? It's dangerous!" I looked at the woman. "Oh! It's you, Mom! You really scared me. Dad said you wouldn't be back for dinner tonight!"

1.
Why did Ken go out that night?
To buy some food.
To ride a bike.
To look for his mother.
To go to cram school.
2.
Why was Ken riding fast on his way home?
His father asked him to go home soon.
He was hungry.
It was getting darker and colder.
Someone was following him.
3.
Who was the motorcyclist?
A policeman.
Ken's mother.
Ken's father.
A stranger.