John and I___friends for eight years.We first got to know each other at a Christmas party.But we_____ each other a couple of times before that.
--- I’ve got your invitation. --- Oh, good. ______
--- Can you find me _______ symbol of China? --- ______ Great Wall.
Bob ________ with us together since he came to our school.
When I came into the teacher’s office, he ________ on the phone.
Tony decided to study abroad _______ he knew he would meet many difficulties.