____crowd of more than 22,000 people gathered near Las Vegas' famous Mandalay Bay Hotel____the Route 91 Harvest Festival. Without____(expect), from the hotel's 32^nd floor, a gunman opened fire on the people below,____ (kill)59 people and at least 500 injured. It was the most____(dead)shooting in US history. President Donald Trump described____as “an act of pure evil”. He ordered US flags to be____(fly)at half-staff to honor those____died. “In moments of tragedy and horror, America comes together as one. And it always ____(have),” Trump said____(Politician) around the world offered their support for the United States.

- Doctor, how are the twins going?                            
- Don't worry. _______of them needs_______.

下列关于铜锌原电池（如图所示）的说法正确的是（　　）

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