sentence1: But they soon discovered that realizing this prospect would require a longer and more arduous journey than they had anticipated. In fact, it would take at least a generation, during which much of the effort of modern life would have to be made, while the fruits of this effort would remain elusive.
sentence2: しかし、まもなく彼らは、この人生モデルの実現は、予想していたよりずっと長くつらい旅になることに気づいた。 実際に、現代生活のために大変な努力を注ぎ込んだとしても、その努力の成果が目に見えてこないため、少なくとも1世代はかかるだろう。