AP News:宾夕法尼亚大学教授罢课

This is AP News Minute.

Hillary Clinton and Donald Trump are set to take the debate stage Wednesday night for one final prime-time showdown in Las Vegas, both candidates facing their own challenges with 20 days to go before the election. For Trump, the debate may be his last opportunity to turn the race around, while Clinton needs to answer new rounds of questions about her authenticity and trustworthiness.

Multiple firefighters were injured in an explosion in Oregon. Fire officials say the explosion occurred as utility workers and firefighters responded to reports of a damaged gasline in northwest Portland.

Professors at 14 Pennsylvania state universities went on strike Wednesday after both sides failed to reach an agreement on a new contract. This is the first strike in the system's 34-year history which affects more than 100,000 students.

And the birth of an 80-pound endangered black rhino is being called an extremely significant event by Iowa zoo officials. With less than 1000 in existence, the zoo says the birth is part of the effort to try and reverse a long decline in the number of black rhinos.

Susan Yee Gaffney, the Associated Press with AP News Minute.