If complete removal of the character data is too extreme and you want to preserve at least the length of each node, a variation on Listing 1 might be useful.

如果彻底删除字符数据过于极端，希望至少保留每个节点的长度，可以使用清单1的一个变体。

youdao

Aerobic exercise (nurture) seems to preserve telomere length with age, but we can't say whether exercising subjects are also genetically predisposed to have better telomere maintenance.

有氧运动(后天的)似乎随着年龄增长可以保护端粒长度，但是我们不能说运动对象是否受基因影响具有更好的端粒修复能力。

youdao

One night in early autumn, with the swampy ground of the Nature Preserve papered with fallen leaves, I was hunkered down to examine a dead snake about a foot in length whose color I thought might in life have been green, when, as I stood, I felt something brush the top of my head.

NEWYORKER: Wakefield