The sentiment is probably assignable to the deep and aged roots which my family has stuck into the soil.

这种情绪可归因于我的家人扎入土壤的深厚而古老的根。

He specifies above a dozen characters which may be found varying even on the same branch, sometimes according to age or development, sometimes without any assignable reason.

指定了十几个字符， 即使在同一个分支上也可发现这些字符不同， 有根据年龄或发展情况， 有有任何可指定的原因。

On the other hand, the new facts have brought new powers; man's physical control over natural forces has been increasing with unexampled rapidity, and promises to increase in the future beyond all easily assignable limits.

另一方面，新的事实带来了新的力量；人类对自然力量的物理控制一直在以前所未有的速度增长，并有望在未来增长到超过所有容易指定的限制。