A teacher was telling her students the importance（重要性) of making others glad.
"Now, children," she said. "Do any of you ever make someone else glad?"
"Yes, teacher," said a small boy. "I made someone glad yesterday."
"Well done. Who was that?"
"My granny."
"Good boy. Now tell us how you made your grandmother glad. "
"Yes, teacher. I went to see her yesterday, and stayed with her for three hours. Then, I said to her: "Granny, I' m going home," and she said: "Well, I' m glad!"
It's          to make someone happy.

A．exciting	B．interesting
C．relaxing	D．important

The boy said he         yesterday.

A．answered a question	B．visited his granny
C．stayed at home	D．went to a party

We can infer from the end of the story that       .

A．the boy was very naughty

B．the boy did a lot to make granny glad

C．granny had a good time with the boy

D．granny hoped to stay longer with the boy