Ⅰ型单纯疱疹病毒复发感染常见的部位是()
A．颊粘膜
B．舌背粘膜
C．舌腹及舌侧缘粘膜
D．唇粘膜
E．唇红及周缘皮肤
参考答案：E
仔细阅读课本P8 的课文，回答下列问题。
1. Who wrote this letter?
______________________
2. When did Jenny write the letter?
3. Who is Danny’s new friend?
4. Whose parents work in a restaurant?
5. Did they play football after school?
计算：
12xy+（3x2-5xy）-2（3xy+2x2）。
