simplescreenrecorder作用：录制屏幕＋摄像头麦克风(主要原因，声音没有延迟。) Record audio->Backend(PulseAudio)->Source(2K USB Camera Mono) ffplay作用：调用本地摄像头，并显示在屏幕，鼠标可以拖动显示框移动。 ffplay -f v4l2 -i /dev/video2 -vf ‘setpts=(RTCTIME-RTCSTART)/(TB*1000000),hflip’
Category: english
The phone after restarting
Password is required after restarting 重启后需要密码 To protect data security, you need to unlock the phone to access all functions. 为保护数据安全，你需要去解锁手机去访问所有功能．
Extreme-animal-2
Fun Facts About Reptiles (爬行动物) A snake’s eyes look as if they are always open and watching. Its eyelids are transparent (透明 的), so you can’t see that they’re closed. If a lizard is caught by the tail, its tail will break off, but it can grow a new one. A hidden crocodile can hold… Continue reading Extreme-animal-2
Extreme animals
Have you noticed that some animals will go to extremes to be noticed? These oddest of creatures come in all sizes and shapes. Some walk in a funny way. Others eat strange things. Some wear bold (明显的), bright patterns to blend in. In this book, you’ll read about the largest and the smallest. You’ll learn… Continue reading Extreme animals
How we measure
How we measure Introduction Lisa and Magda are pen pals. Lisa lives in the United States, and Megda lives in Canada. A lot of things are the same in the United States and Canada. But many things are different. One difference is the system people use to measure things. Canada uses the metric system to… Continue reading How we measure