【答案】：
1. B
2. A
3. B
4. B
5. A
【解析】：
1. 答语“I'm from China.”表明是来自哪里，问句应是询问来自哪里，“Where are you from?”符合，选B。A选项是一般疑问句，回答应用Yes或No。
2. 答语“Great! Thank you.”，“How are you?”询问身体或情况如何，回答后一般不用感谢；“Nice to meet you.”的常见回答是“Nice to meet you, too.”，这里A选项“How are you?”更符合语境，选A。
3. 答语“I'm twelve years old.”说明问句是询问年龄，“How old are you?”用于询问年龄，选B。A选项询问生日时间。
4. 答语“We have English, math, science and art.”说明问句是询问有什么科目，“What subjects do you have in your school?”符合，选B。A选项是一般疑问句，回答应用Yes或No。
5. 答语“Three classes in the morning and two in the afternoon.”说明问句是询问每天有多少节课，“How many classes do you have each school day?”符合，选A。B选项询问今天有什么课。
