They focus on keeping their soil rich and free of disease.

农民关心的是保持土壤肥沃并且免受病害。

After months of observation at the natural history museum, officials confirmed that Juliet was free of disease.

在该自然历史博物馆进行了数个月的观察之后，官员确认朱丽叶没有染病。

" It will be interesting to know, " he said, " how well the technique worked… whether the babies are free of disease and whether there is any risk of them developing problems later in life."

“这将是一件有趣的事情，”他说，“要知道这项技术的效果如何，婴儿有无疾病，以及他们在以后的生活中是否有出现问题。”