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？