Edison was the first scientist ____ a modern research and development center. [ ]

A. built

B. having built

C. to build

D. to be building

“月亮弯弯弯上天，／牛角弯弯弯两边，／镰刀弯弯好割草，／犁头弯弯好种田。”这首广东传统儿歌集中体现了儿歌的（）功能。

A.陶冶情性

B.启迪心智

C.训练语言

D.矫正发音