KNOW IT ALL: Wednesday's Top 6 Stories at NBC News

Image: Ebola in Liberia

A Liberian nurse sprays disinfectant as a prevention against the deadly Ebola virus in the waiting area outside the ELWA isolation unit in Monrovia, Liberia on August 2. AHMED JALLANZO / EPA

Good morning, and happy Wednesday. Here are some of the stories we're following today:

1. Americans are fed up with Congress and the president

President Barack Obama’s overall approval rating hitting a new low at 40 percent in the latest NBC News / Wall Street Journal poll. But that's a whole lot better than Congress' approval rating, which landed at a mere 14 percent. Americans hold congressional Republicans in lower regard than congressional Democrats, but no one in Washington exactly wins in this poll. Nearly three-fifths of Americans say they are upset enough by something going on in the country that they'd be willing to hold a protest sign for a day. Read more in POLITICS.

2. Death of Two-Star Army General is a rare killing

The death of U.S. Army Major Gen. Harold Greene on Tuesday marks the first time an officer with a major general rank or higher has been killed fighting overseas since Vietnam. A lone Afghan gunman is accused of ambushing more than a dozen Western soldiers who were visiting the Afghanistan National Military Academy in Kabul. Also wounded in the attack was a German brigadier general and several Americans. Read more in NEWS.

3. Health officials scramble to prevent Ebola outbreak in Nigeria

Eight people who came into contact with American consultant Patrick Sawyer, who died of Ebola last month in Nigeria, have been quarantined and dozens more are being watched for symptoms. The Ebola outbreak in Africa, the worst in history, has mostly been in three countries — Sierra Leone, Guinea and Liberia, where Sawyer traveled from. Experts warn that an outbreak in Lagos, Nigeria, would be the "worst case scenario," because it is so densely populated. The CDC has four experts in Nigeria and plans to send more. Read more in NEWS.

4. Army Sgt. Bowe Bergdahl questioning begins

Army Sgt. Bowe Bergdahl will be questioned as part of the investigation into his disappearance in Afghanistan five years ago. Bergdahl and his lawyer are meeting with Maj. Gen. Kenneth R. Dahl, the Army's investigator on the case. The questioning will be something like a police grilling, but with a few extra rules and procedures. The investigation could clear Bergdahl of any wrongdoing, lead to a court-martial or something in between. Read more in NEWS.

5. Hawaii in for a double-whammy of storms

Hawaii could be in for a one-two hit starting Thursday. Iselle, currently a Category 2 hurricane might weaken but could still hit Hawaii hard. Right behind, hurricane Julio was packing maximum sustained winds of 75 miles per hour, as it developed from a tropical storm to the fifth hurricane of the season. Read more in Weather.

6. First killer put to death after botched Arizona injection

Michael Worthington was executed by lethal injection in Missouri for raping and killing a female college student in 1995. Worthington was pronounced dead 10 minutes after the drugs were administered, which was considerably different from the Arizona execution last month in which a double-murderer gasped and snorted for nearly two hours after the lethal injection. Read more in NEWS.

What’s trending today?

Like a yearbook superlative page for celebrities — Vanity Fair's International Best-Dressed List has been released. On it, Pharrell Williams, known for his distinctive hat; Lupita Nyong’o, who always wows on the red carpet; and Kate Middleton, who wows everywhere, even during Prince George play-dates.

Image: Lupita Nyong'o
Lupita Nyong'o arrives at the Oscars on Sunday, March 2, 2014, at the Dolby Theatre in Los Angeles. Chris Pizzello / Invision via AP, file