dentifying the Problem
Highlight details that help you find the problem.

The phone rang two days before Christmas. The moment investigator Will Hughes heard what the caller had to say, he knew he was facing a deadly health emergency. A diseased cow had been found–and many lives were at risk.

Early that morning, a tissue sample from a cow in Washington State had tested positive for bovine spongiform encephalopathy (BSE)–also known as mad cow disease. What is the problem?