A、He was wondering if the speaker was used to living in America. B、He was trying to show friendliness to the speaker. C、He wante

I had flown from San Francisco to Virginia to attend a conference on multiculturalism. Hundreds of educators from across the country were meeting to discuss the need for greater cultural diversity in the school curriculum. I took a taxi to my hotel. On the way, my driver and I chatted about the weather and the tourists. The driver was a white man in his forties. How long have you been in this country? he asked. All my life! I replied, I was born in the United States.  With a strong southern accent, he re! marked, l was wondering because your English is excellent. Then I explained as I had done many times before, My grandfather came here from China in the 1880s. My family has been here in America for over a hundred years. He glanced at me in the mirror. Somehow, I did not look American to him. My appearance looked foreign. Questions like the one my taxi driver asked make me feel uncomfortable. But I can understand why he could not see me as an American. He had a narrow but widely shared sense of the past: a history that has viewed Americans as descendants of Europeans. Race has functioned as some thing necessary to the construction of American character and quality. In the creation of our national identity, American has been defined as “white”. But America has been racially diverse since our very be ginning on the Virginia shore, where the first group of Englishmen and Africans arrived in the 17th centu! ry. And this reality is increasingly becoming visible everywhere.
Questions 16 to 18 are based on the passage you have just heard.
16. What was the theme of the conference the speaker was to attend?
17. Why did the taxi driver ask the speaker how long he has been in the US?
18. What message did the speaker wish to convey?