乙酸和乙醇在浓硫酸的催化下发生酯化反应时,乙酸分子中断键的位置是( )
A:a
B:b
C:c
D:d
完形填空
Look at this girl. 1 name is Wang Meimei. 2 is twelve. Wang Ming is her brother. He is3 Class Three,Grade Two. Do you know how old he is? He is fourteen years old. The brother4 sister are in No. 2 Middle School. Their mother5 a teacher. She is an6 teacher. Their father, Mr Wang, is a teacher, 7. He is a Chinese teacher in No. 8 Middle School. Their students all love them because they love their students. They have(有) a cat.8 name is Mimi. 9 a nice cat. The cat and Wang Meimei are 10friends.
读如图所示的“岩浆岩形成示意图”,回答问题。
世界著名经济史学家贡德弗兰克认为:“11世纪和12世纪的宋代,中国无疑是世界上经济最先进的地区。自11世纪和12世纪的宋代以来,中国的经济在工业化、商业化、货币化和城市化方面远远超过世界其他地方。”下列史实不能够印证材料观点的是( )