1. These trees are noted for their straightness and hardness. 这些树的特点是树干挺直，木质坚硬。
2. A new algorithm of minimum zone method for evaluating straightness error is put forward in this paper. 提出了最小区域法评定直线度误差的新算法———缩小约束域的有效特征点法。
3. The results show that the device can avoid the influence of bad straightness of the pipe and advance the machining quality. 研究结果表明，此夹紧装置能够避免钢管不直度的影响，提高钢管加工的质量。
英英解释
n.
1. of hair: lack of a tendency to curl
2. freedom from crooks or curves or bends or angles
3. trueness of course toward a goal
4. having honest intentions
5. a sexual attraction to (or sexual relations with) persons of the opposite sex
