Various kinds of vehicles run to and fro in the street.

　　大街上往來的`車輛很多。

　　He hopped to and fro between London and Paris for the business.

　　為了這筆生意他曾不停地往返于倫敦和巴黎。

　　Your thoughts cannot be tossed to and fro like the waves of the sea.

　　你的思考不能像大海的波浪一樣起伏。