like: 循环 → →
Blutkreislauf ☊ 
血液循环 ☊ xuě yè xún huán Kreislaufprobleme ☊ 循环系统问题 ☊ xún huán xì tǒng wèn tí 
循环 → ☊ xun2huan2 
to cycle; to circulate; circle; loop ☊ 
Chu kỳ ☊ 自行车 ☊ → 循环 ☊ → ☊ → 
cycle Blutkreislauf ☊ 血液循环 ☊ xuě yè xún huán Kreislaufprobleme ☊ 循环系统问题 ☊ xún huán xì tǒng wèn tí