Lucy knows how to add and substract but fractions have her up a stump.

做加减法，露西不成问题，可分数却难倒了她。

Substract: Venture Capital in the forestry Hi-Tech industry has been studied in this article.

本文对我国林业高新技术产业创业投资问题进行了研究。

Differences in performance between coated tools explained through a separate consideration of substract and coating influences.

通过分别考虑基体和涂层的影响，阐明了涂层刀具之间性能的原因。

The invention provides a magnetic element capable of reducing configuration area relative to a mounting substract and realizing high density mounting.

本发明提供一种减小针对安装衬底的配置面积、可实现高密度安装的磁性元件。

Objective:To evaluate the clinical value of Digital substract angiography (DSA) and endovascular stent placement (ES) in the diagnosis and treatment of aortic dissection.

目的：探讨数字减影血管造影（DSA）和经皮带膜内支架置入术（ES）在主动脉夹层诊断和治疗中的应用价值。