苦心的英文：
painstaking
- They dig into the history of mankind
他们苦心研究人类史。 - The book was the result of ten years' assiduous research.
那本书是十年苦心钻研的成果。 - I saw him puzzle over a math problem.
我看见他正在苦心思索一道数学题。 - Add to that the good war of a born eavesdropper, carefully honed on a lot of strangers in foreign train compartments
此外，他生就一对善于偷听的耳朵，经过在异国火车车厢里听众多陌生人谈话的苦心磨练，变得更灵敏。
n. 辛苦；勤勉
adj. 辛苦的；勤勉的；小心的
- The experts did a painstaking sifting of debris.
专家们对岩屑进行了煞费苦心的研究。 - Solvable or comprehensible only with painstaking effort.
难理解的只有经过刻苦的努力才能解决或理解的 - It was this painstaking apprenticeship that gave Van Gogh mastery of painting.
这种辛勤的练习，使梵高精通了绘画技巧。 - His painstaking to attain his goal in life is praiseworthy.
他为实现人生目标所下的苦功是值得称赞的。 - It also meant the beginning of obligation, painstaking, happiness and enjoyment.
它同时也意味着责任、辛苦、幸福、快乐的开始。
