牙源性腺样瘤多发于（）
A.10岁以下
B.10～19岁
C.20～29岁
D.40岁以上
E.50岁以上
参考答案：B
A．该溶液lmL稀释至2mL后，pH等于2
B．向该溶液中加入等体积、pH为13的氢氧化钡溶液恰好完全中和
C．该溶液中硝酸电离出的c（H+）与水电离出的c（H+）之比值为10-12
D．该溶液中水电离出的c（H+）是pH为3的硝酸中水电离出的c（H+）的100倍
Directions:
Write a letter to invite your best friend Jane to take part in your mother’s 60-year-old birthday and inform her of your arrangement.
Begin your letter as follows.
Dear Jane,
You should write about 100 words on ANSWER SHEET 2. Do not sign your own name, using "Li Ming’ instead. Do not write the address.
