ST Petersbury was in ruins:_______fires burned everywhere.

This is the book _____ the teacher spoke in class.

It is reported that two schools，________ are being built in my hometown，will open next year.

I have bought 2 ballpens, _______ writes well.

----- It is 30 years since we last met.
------ But I still remember the story, believe it or not, _________ we got lost on a rainy night.

In our class there are 60 students, of ____________ two thirds are boys.

We are in close contact with local authorities and it is a situation __________  we will keep a very close eye on.
A. where           B. when            C. which            D what

. The book, _______ is blue, is mine.

Xi’an was the last city ______ he visited when he came to China.

The music ______ she is dancing sounds beautiful.