Illegal immigration poses a particular challenge.

非法入境者的统计也是一大挑战。

But the backlash against illegal immigration has been so severe among voters in Republican primaries that it will be a brave senator who touches the subject.

但是，在共和党初选中，选民对打击非法移民反应及其强烈。参议员要想触及这一话题还需足够的勇气。

China has been cooperating with the US and other countries to combat illegal immigration that undermines the normal order of entry and exit among countries.

在非法移民问题上，中方一直与包括美国在内的其他国家开展合作，打击这种破坏国际间正常出入境秩序的做法。

Australian immigration has moved from family immigration to more of a skills based immigration. Unlike us, they don't face massive levels of illegal immigration.

而澳洲的移民政策已经从青睐全家移民转向技术移民，所以不像我们这样面临良莠不齐的非法入境人群。

The Command & Control Center will be located in Constanza and will provide alerts about possible threats, including drug trafficking, illegal immigration, and smuggling.

拨装备了雷达和光电的传感器、无线电网络和指挥控制中心。