4 . In the rich countries of the West, the electric vehicle revolution is well underway. Climate-conscious consumers drive Teslas or Polestars for reasons of morality and fashion. Poorer countries are also experiencing a wave of electrified trend. In Bangladesh, electric three-wheeler taxis, known as tuk-tuks, are rapidly replacing gas-powered ones on the streets. Such electric vehicles are climate friendly, cost effective, and help reduce air pollution.

Yet a glance under the hood (引擎盖) of these vehicles reveals a poisonous secret: each tuk-tuk runs on five massive lead-acid batteries, containing almost 300 pounds of lead in total. Every year and a half or so, when those batteries need to be replaced and recycled, about 60 pounds of lead leak into the environment. Battery recycling, often at small-scale unregulated factories, is a highly profitable but deadly business.

Lead is dangerous, and any exposure to it is harmful to human health. Lead that has entered the environment hurts people on an extraordinary scale. The numerous ways lead enters air, water, soil, and homes across the developing world — and the enormous damage it does to human health, wealth, and welfare — causes one of the biggest environmental crises in the world yet receives little attention.

The World Bank estimates that lead kills 5. 5 million people per year, which would make it a bigger global killer than AIDS, malaria, diabetes, and road traffic deaths combined. On top of the shocking deaths, the social burden of lead poisoning is extraordinary, as is its contribution to global inequality — our research on the cognitive effects of lead poisoning suggests that it may explain about one-fifth of the educational achievement gap between rich and poor countries.

But unlike many challenges faced by developing countries, lead poisoning is a problem that is fixable with some attention and a relatively modest financial investment. Better monitoring, research, and rules can help protect children all over the world from the dreadful effects of lead poisoning and reduce the massive global costs it brings.

Light pollution is a serious problem. This became completely obvious when the World Atlas of Artificial Night Sky Brightness, a computer-created map based on thousands of satellite (卫星) photos,     1     (publish) in 2016. The map shows how and where     2    (we) world is lit up at night. Large areas of North America, Europe, and Asia are glowing (发光) with light, while only the most remote (偏远的) places on Earth are in total darkness. Some of the most light-polluted    3     (country) in the world are Singapore, Qatar, and Kuwait.

Sky glow is the brightening of the night sky, mostly over cities, because    4    the electric lights of cars, streetlamps, offices, factories and buildings, turning night into day.

People     5     live in cities with high levels of sky glow have a hard time     6     (see) stars at night. Scientists are     7     (particular) worried about sky glow pollution as it influences their ability     8     (view) space.

According to research, more    9     80% of the world’s population, and 99% of Americans and Europeans, live under sky glow. It sounds pretty, but sky glow    10    (cause) by human activities is one of the most common forms of light pollution.

At the Shishou Milu National Nature Reserve in Hubei Province, about 2,000 creatures wander freely. Their numbers include 460 deer born this year, showing that the species,     1     was once endangered in China in the early 20th century, has staged a remarkable     2     (recover).

Often     3     (refer) to as sìbuxiang, a milu deer seems to consist of parts of various creatures. It has antlers (鹿角) like other deer, but seems to have the head of a horse, the feet of cattle and the tail of a donkey (驴).

    4     one of the animal’s three major protected areas in China, the Shishou reserve was established in 1991. Close to the Yangtze River, the area has a complete wetland ecosystem,an ideal habitat for the deer. Its conservation story provides     5     example for other endangered animals under a threat of extinction.

    6     (ensure) a safe environment, two engineers and eight rangers (护林员) are sent to get around the reserve. Advanced technologies are applied to help observe and analyze     7     (they) habits and environment. The efforts of those responsible for the deer have     8     (significant) resulted in the increase in numbers.

In the     9     (country) three major protected areas the Nanhaizi Milu Park in Beijing, the Dafeng Milu National Nature Reserve in Jiangsu Province, and the Shishou reserve——the number of the animal     10     (increase) from 39 to over 10,000 since 1986.

10 . Are flash floods becoming more severe? Natural disasters are generally getting worse—and that's true for floods, too.

As climate change warms the atmosphere, extreme rainfall is rising, which increases the risk of flash floods. Heavy precipitation(降水) events are predicted to increase by 2 to 3 times the historical average. The Federal Emergency Management Agency expects the nation’s floodplains to expand by 45 percent by the end of this century, as the agency reported in a recent study. A study in early 2021 found that increased precipitation—resulting partially from climate change—costs the US an additional $ 2.5 billion each year in flood damage. And some studies show that flood frequency was increasing in the Mississippi River valley and across the Midwest in the last century, as well as in the Northeast over the past 50 years.

There are several steps you can take to prepare for flash floods

First, know the level of risk by looking at flood maps. You may be required to have flood insurance if you live in a high-risk area.

Pay attention to flash flood watches, which the National Weather Service issues to indicate when conditions could result.in flash floods. People in these areas-should be-ready to take action—particularly if the NWS announces a flash flood warning. That’s issued when flash floods are approaching and, at that point, people should immediately leave the area.

But be particularly careful when travelling by car. Don’t drive through flooded streets—it's difficult to judge the water depth, and roadways hidden below the water can collapse. If floodwaters cause your vehicle to lose control, abandon it and seek the higher ground. Rapidly rising water can sweep the vehicle away. Know your surroundings and head to the higher ground, and listen to the radio updates when in a flood.

It’s also important to develop an emergency prepared plan with your family or those you live with to have a few days’ worth of resources.