- 重点词汇
- 红桃
heart
- 免费
free； be free of charge； be cost-free
- 在线
be online； (of science and technology) be controlled by a certain system
- 观看
watch； view； see
- 历史
history； past event； historical record； history (as a branch of learning)
- 视频
video clip/footage； video frequency； video-chat (with sb)； have a video chat (with sb)
