An insecure computer system is an opendoor to criminals.
不安全的电脑系统给罪犯提供了可乘之机。
《牛津词典》
2
Do not open the protection ( gates ) door of machine without permission. Do not change ordelete the system documents of the machine.
未经允许不得打开机床电器防护门，勿要对机内系统文件进行更改或删除。 综。
3
This traditional international order came into fierce col l ision with the modern international system when Western powers determined to make China open its door to them, with great losses for China.