单词:friction(al) force
单词:friction(al) force 相关文章
Key Local Afghan Police Force Slow to Catch On Coalition planners say they need 100 police officers to secure Marzak. Village elders promised at least that many men would volunteer for a new Afghan Local Police force. But by late January, fewer than
A recent study estimates 66,000 homosexuals currently serve -- about two percent of the total in uniform. In 2002, David Hall was an Air Force sergeant studying to be an officer, pursuing his dream of becoming a military pilot. But once his sexual st
A: Good morning, this is Ray speaking. Is Lee in? B: Hi, Ray. This is Lee. A: Good morning, Lee. How is it going with you today? B: Things are wonderful. What can I help you with? A: Could we meet for lunch tomorrow to discuss the new project? B: Tha
Hello, I'm Justin Greene with the BBC news A video sent to the Nigerian government by the Islamist group Boko Haram appears to prove that some of the 276 girls kidnapped two years ago in the town of Chibok are still alive. The images apparently filme
Why Frisbees Fly With a gentle flick of the wrist on a warm summer day, you can launch a frisbee on a long and graceful flight. Why do they fly so well? One reason is something called gyroscopic force. This is the tendency of a spinning object to mai