拨打校内电话怎么说英语

To make a call to a phone inside a school in English, you can say "Can I have the extension for [person's name or department] please?" or "Can you connect me to [person's name or department] please?" If you know the extension number, you can say "Can you connect me to extension [extension number] please?"
For example:
"Can I have the extension for the science department please?"
"Can you connect me to Ms. Smith's office please?"
"Can you connect me to extension 345 please