某同学选用如下图片进行研究性学习。那么应确定的研究主题是(   )

“中东水塔”指的是：

印度实行“绿色革命”是指（    ）

完成对话
A: How was your vacation, Fred?
B: ____ .
A: ____ ?
B: I went to the U.S. with my parents.
A: Cool! ____  in the U.S.?
B: First we went to Los Angeles(洛杉矶). My uncle lives there. Then we went to New York to see my cousin.
A: ____ ?
B: It was a little warm but sunny.
A: Did you see any movie stars in Los Angeles?
B: No, but I saw Tom Cruise in New York. He was at a restaurant! I got his autograph.
A: Wow! That’s great!  What else did you do in New York?
B: Hmm…Oh yeah, I also went to Central Park.____ there! .