If you travel, try to avoid riding a bicycle.

　　如果出行盡量避免騎自行車。

　　Riding a bicycle again? How long will you insist?

　　又在騎單車啦?要堅持多久啊?。

　　This time he had no truck; he was riding a bicycle!

　　這回他沒有開車，而是騎著輛自行車！

　　She had her foot hurt while riding a bicycle yesterday.

　　昨天在騎自行車的時候她的腳受傷了。

　　When did you see him riding a bicycle on the playground?

　　你何時看到他在操場上騎自行車的？