美国1964年肯尼迪总统50美分银币

[视频作者] 电场高斯定理

[视频时长] 3:10

[视频类型] 日常

We choose to go to the moon! We choose to go to the moon! We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard.