build up a bussiness by years of effort and persistence; keep(an enterprise,etc) going by painstaking effort;take great pains to carry on one’s work under difficult circumstances; take no end of pains to do sth; take pains with the work
❍ 在过去二十年里，他～，坚持搞他的科学试验。In the past twenty years he took no end of pains to persist in his scientific experiments.
惨淡经营
take pains to do something; build up a business by laborious effort and persistence;keep an enterprise going by painstaking efforts;take great pains to carry on one’s work under difficult circumstances
惨淡经营cǎn dàn jīnɡ yínɡ
惨淡：煞费苦心。比喻费尽心思谋划某事。take great pains to carry on one’s work under difficult circumstances, keep going by painstaking effort