RAMDAC中文名为数模转换器，作用是（），DirectX作用是（）。
参考答案：将数字信号转换为模拟信号；加强电脑的多媒体性能
Have you really realized the part computers have _____ in the daily life? [ ]
A. made
B. given
C. caused
D. played
提高汽油收率须采取什么措施？
