题目内容：

Summers around the world are already warmer than they used to be, and they are going to get dramatically hotter by the century’s end if carbon pollution continues to rise. That problem will be felt most acutely in cities.

The world’s rapidly growing population coupled with the urban “heat island” effect, which can make cities up to 7.8℃ warmer than the countryside, adds up to a recipe for dangerous and potentially deadly heat.

Currently, about 54 percent of the world’s population lives in cities, and by 2050 the urban population is expected to have grown by 2.5 billion people. As those cities get hotter, weather patterns may shift and make extreme heat even more common. That will, in turn, threaten public health and the economy.

Under the high-pollution situation, currently mild Ottawa, Canada could have the tropical climate of Belize City by 2100. Mountainous Kabul, Afghanistan could feel like coastal Colombo, India. Already hot Cairo, Egypt could feel like its sweltering (闷热的) neighbor, Abu Dhabi.

The average land temperature is projected to rise 4.8℃, but due to the differences in geography, some cities will warm much more. Sofia, Bulgaria is predicted to have the biggest overall temperature shift, with temperatures rising nearly 8.4℃ by 2100. That would make its summers more like in Egypt.

The average summer temperature in Khartoum, Sudan is projected to skyrocket to 44.1℃ if carbon pollution continues to be unchecked. That shift emphasizes that unless carbon pollution is limited, the planet could be headed toward a state that humans have never experienced.

Dealing with less extreme heat makes adaptation easier and less expensive, and given that choice, perhaps it’s no surprise cities are leading the charge on climate change. They face the worst impacts of extreme heat and are home to billions. That’s why thousands of mayors from around the world have banded together and promised to reduce their emissions. That includes lots of U.S. cities committing to meet the Paris Agreement goals after President Trump announced he was pulling the U.S. out of the agreement.

1.What may happen by the end of the century according to the passage?

A. Carbon pollution will be worse and worse.

B. The world’s population living in cities will decline.

C. The temperature in cities will be too high to bear in summer.

D. The economy and population will be impacted severely by pollution.

2.Which city mentioned in the passage will have the greatest climate change?

A. Ottawa, Canada.    B. Sofia, Bulgaria.

C. Khartoum, Sudan.    D. Kabul, Afghanistan

3.The underlined word “skyrocket” in the sixth paragraph probably means “      ”.

A. rise rapidly.    B. change gradually

C. reverse completely    D. drop naturally

4.What can we learn from the last paragraph?

A. Dealing with the climate problems right now is hard and expensive.

B. Officials are unwilling to deal with climate change.

C. Extreme heat will have no impact on the climate in the countryside.

D. Many U.S. cities are dealing with climate problems actively.