翻译成英语 义务鲜血

voluntary blood donation 义务献血,非英语国家一般用这种
donate blood 无偿献血比较正式点,美式英语

义务献血 voluntary blood donation

学校贴出了义务献血的号召书。
An appeal of voluntary blood donation was put up in the school

Voluntary blood翻译得超级标准啊，哈哈

blood donate

donate blood voluntarily.

Voluntary blood