英语翻译Most of his time / life was devoted to the cause of scie

可以用spend,
用被动spent(spended是错的),介词to换成on

不可以.换成spend的话意思有改变.
Most of his time/life was spent on the cause of scientific research.
读起来有一种他浪费了他的时间的感觉

可以
用spent
后面to用on替换

be devoted to 与 spend有几个差别：
（1）be devoted to指奉献、致力，含主动、积极之意。spend有“花费时间”之意。原句意思是献给了科学研究事业，故不能用spend。
（2）spend 后面不接to，需接for、on或in。例如，Most of his time was spent for the cause of scientific res...