The beauty of the city ________ its magnificent buildings．（　　）

My father is going to shop____3o’clock____the afternoon____ March 23rd.

We’ll have our picnic in the place _____ most of us like best.

You must be tired now, Bruce. ______ you have been driving non-stop for at least two hours.

Only when all the fish in the lake died _____ how serious the pollution was.[ ]