托福听力真题原文+题目+答案+mp3下载：a muon detector
Listen to part of a lecture in an Archaeology class.
P: Talking about one popular myth in Archaeology, some people simply think excavation is digging the site until something valuable is found. Well, while there is an element of luck involved, we have an array of high tech devices to help us figure out where to put our efforts. You know, we can't just dig up the site randomly looking for an ancient structure. There is one of the newer tools actually created by a different field of study.
The machine relies on particle physics. Um... interdisciplinary I'd say.And it is called a muon detector, or counter. Muon is a charged elementary particle similar to electron. Okay, let me start over. On Earth, most naturally occurring muons are created by cosmic rays, which consist mostly of protons, many arriving from deep space at very high energy. When these charged particles of cosmic rays collide with molecules in the upper atmosphere, they break up into smaller particles, muons.Traveling at the speed of light, muons can penetrate tens of meters into rocks and other matter on Earth's surface.
Question 1 of 6
What is the lecture mainly about?
O A. Misconceptions about muon detectors in Archaeology
O B. An excavation of an ancient structure using a muon detector
O C. The collaboration between physicists and archaeologists in the development of the muon detector
O D. Benefits that archaeologists can obtain from muon detectors
Question 2 or 6
What feature of the muons benefit archaeologists?
O A. Their ability to carry information fromouter space
O B. Their ability to break down cosmic rays into smaller particles
O C. Their ability to pass through solid material
O D. Their ability to travel at the speed of light
8元有偿下载托福听力真题原文+题目+答案+mp3下载：a muon detector