一、含有be动词的句型变换1. There are some American friends in our school.(改为一般疑问句)_there_American friends in your school?2. He is an English teacher.(改为一般疑问句) _he an English teacher?3. My favorite subject is biology.(改为一般疑问句)_ _favorite subject_?4. My math teacher is Mr. Smith.(改为一般疑问句)_ _ math teacher Mr. Smith?5. Tom and John are studying in the room.(改为一般疑问句)_Tom and John _ in the room?6. Those are their pencilcases.(改为一般疑问句,并作肯定回答