乙酸酐-乙酸钠酰化法测羟基时,加入过量的碱的目的是( )。
A.催化
B.中和
C.皂化
D.氧化
参考答案:C
125×8的积的末尾有______个0;204×4的积中间有______个.
单词拼写。
1. It's hot today. Let's go swimming in the s_________.
2. —I'm a teacher, what's your j_______? —I'm a reporter.
3. My grandfather has two sons. One is my father, the other one is my u______.
4. The teacher said that the m________ goes around the earth.
5. This place is so beautiful that many artists often come here to d______ pictures.
6. —Would you like some more noodles? —No, thanks. I am ________(饱的).
7. It is __________(礼貌的) to wait in line.
8. Mother said to her little daughter, "You are old enough to look after_________(你自己)."
9. As a student, you shouldn't __________(抄袭) other's homework.
10. My teacher often told me to pay ________(注意) to my spelling while I was writing.