Jimmy didn’t notice his head teacher entering his bed room. He _____a phone call.

—Haven't seen you for ages! Where have you been? —I went to Ningxia and    there for one year, teaching as a volunteer. 

They became friends again that day. Until then, they _____ to each other for nearly two years.

James has just arrived, but I didn’t know he _______ until yesterday.

 —Have you known Dr. Jackson for a long time?—Yes, since she _________ the Chinese Society.