1.  

John, ____ I’ve always considered to be my best student, did very poorly on his test yesterday.

2.  

In the summer I will go to Santorini, _____ is a beautiful Greek island.

3.  

The passenger, _____ seatbelt was not fastened, was the one most injured.

4.  

______ shoes are these?

5.  

The girl, _____ mother was just here, has forgotten her schoolbag in the classroom.