free passes

Exoenzyme is an important type of soil enzymes, which passes through plasma membrane after synthesized in the cell and functions in free state in the environment.

胞外酶是土壤酶的一种重要类型，指在细胞内合成后穿过细胞质膜以游离态存在于环境中的酶。

The Precheck free trial has confused some travelers including Dr. Van Bennekom, the Northeastern University professor who routinely get boarding passes printed with 'TSA Precheck' and assume they are now enrolled in the program.

Precheck的免费体验把一些旅客弄得稀里糊涂其中包括东北大学的教授范贝内科姆他们的登机牌上通常都印有TSA Precheck字样，于是自以为他们现在已经注册加入了该项目。

To issue free passes for ( a theater, for example ).

提供免费入场券 ( 如剧院 )

The distance or angle that the executer unit passes since free position to action position.

操动器从自由位置移动到动作位置所经过的距离或角度.