关于CT值的叙述，正确的是（）

A.脂肪的CT值一般比水高

B.CT值标尺中，骨的上限是+2000

C.根据图像显示和诊断的需要，设置的一组数值

D.目前，CT值的百分比标尺是2%

E.是根据X线对人体软组织的衰减而设置的

短文改错 （共10小题；每小题1分，满分10分）

Did you enjoy yourself yesterday? I suppose you do. But I’d like to tell you what a bad day I had yesterday. Everything just went wrongly. On the morning, my alarm clock didn’t ring, since I woke up an hour late. I was in such a hurry that I burnt my hand when I was cooking the breakfast. Then I ran out of the house to catch the 8:30 buses. This is the bus I usually take. But, you may laugh, I missed it of course. I am very unhappy, and scared as well because teacher hates the students coming late to school. So I ran three miles to school only to found that nobody was there. The school was quiet but peaceful. Our classroom was locked. I realized that moment: It was Sunday.