selection pressure的用法和样例：
例句
- During breeding for vertical resistance, horizontal resistance tends to decline because of negative selection pressure.
当培育垂直抗性时，由于负的选择压力，水平抗性趋于下降。 - Selection pressures pull in different directions, and the adaptation that results is some kind of compromise.
选择压力往不同的方向拉，结果产生的适应是某种类型的妥协。
