One of the biggest misconceptions about #trees is that most species have a deep root system that match the size and shape of the tree's crown. For most temperate species, however, roots extend laterally outwards - sometimes up to 2 or 3 times the length of the tree's spread, and rarely go deeper than 3 feet. Of course, there are species that are adapted to super dry soils and can send roots extremely deep underground in search of water, but about 80% of studied trees have a root system that usua

1.3 Length, Concatenation, Reverse, Null, Substring, Prefix, Suffix on Strings | TOC Lecture

13 冠词+there be结构【英文 语法】