根据所给汉语提示,写出空缺处单词正确形式.
1. How long have you _____ (学习)English?
2. Mr. Wang _____ (教) us Chinese.
3. My father knows our _____ _____ (校长).
4. When did you _____ (到达) in Beijing?
5. Mr. Smith has taught English in that school _____ (自从) he came to China.