题目选项分析

In 2006 Cameron Chibuike, a staunch advocate for increased cargo border control, testified in a Congressional hearing that, as a demonstration, an undercover investigator of his had successfully smuggled radioactive material into the United States, which was a feat supposedly impossible given cargo radiation detectors first introduced in 2005 and they are now installed in a majority of U.S. border checkpoints.

In 2006 Cameron Chibuike, a staunch advocate for increased cargo border control, testified in a Congressional hearing that, as a demonstration, an undercover investigator of his had successfully smuggled radioactive material into the United States, a feat supposedly impossible given cargo radiation detectors first introduced in 2005 and now installed in a majority of U.S. border checkpoints.