题目

The alarm clock was ringing! I got out of bed and walked over to my desk and turned it off. It was 6:30 in the morning and I was very tired. It was very ___21___ outside and I couldn’t see anything! My mother was already ___22___ and told me to go and take a shower because I was going to be late for ___23___. I took a shower for about ten minutes and then I came out and took my towel and ___24___ myself. Then I got my ___25___ and put all my books in it so I wouldn’t forget anything when I went to school. I walked to the ___26___ so that I could make myself some food. I ate and ___2若的值为零，则x的值是 [     ]A.±1 B.1 C.-1 D.不存在