问题
单项选择题 A1/A2型题
下列关于窗位的概念正确的是（）
A.窗位相当于显示灰阶的中心
B.不同机器的窗位值
C.窗位与所显示的组织CT值无关
D.通常窗位选择以水的CT值为标准
E.窗位规定所显示CT值的范围
答案
参考答案：A
解析：窗位是应选择欲观察组织CT值的中心值，又称窗中心。
搜题请搜索小程序“爱下问搜题”
下列关于窗位的概念正确的是（）
A.窗位相当于显示灰阶的中心
B.不同机器的窗位值
C.窗位与所显示的组织CT值无关
D.通常窗位选择以水的CT值为标准
E.窗位规定所显示CT值的范围
参考答案：A
解析：窗位是应选择欲观察组织CT值的中心值，又称窗中心。
Many people catch a cold in the springtime or fall. It makes us wonder… if scientists can send a man to the moon, why can't they find a cure for the common cold? The answer is easy. There are actually hundreds of kinds of cold viruses out there. You never know which one you will get, so there isn't a cure for each one. When a virus attacks your body, your body works hard to get rid of it. Blood rushes to your nose and cause a block in it. You feel terrible because you can't breathe well, but your body is actually eating the virus. Your temperature goes up and you get a fever, but the heat of your body is killing the virus. You also have a runny nose to stop the virus from getting into your cells. You may feel miserable, but actually your wonderful body is doing every- thing it can to kill the cold. Different people have different cures for Colds. In the United States and some other countries, for example, people might eat chicken soup to make themselves" feel better. Some people take hot baths and drink warm liquids (流汁). Other people take medicine to stop Various symptoms (症状) of colds. There is one interesting thing to note" some scientists say taking medicines when you have a cold is actually bad for you. The virus stays in you longer because your body doesn't have a way to fight it and kill it. Bodies can do an amazing job on their own. There is a joke, however, on taking medicine when you have a cold. It goes like this: It takes about one week to get over a cold if you don't take medicine, but it takes only seven days to get over a cold if you take medicine.
|