Many strange things happened before Tangshan earthquake happened. The well walls had deep cracks. Some     1     (smell) gas came out of wells. Chickens and even pigs were too nervous to eat.     2     3∶42 a.m. on 28 July 1976, everything began to shake. It seemed as if the world     3     (come) to an end. Hard hills of rock became rivers of dirt. In less than one minute, the whole city     4     (lie) in ruins. Two thirds of the people died or were injured. Everything in the city was     5     (destroy). People were shocked at this and wondered how long the disaster would last.

The army organized teams to dig out those     6     were trapped and to bury the dead. Workers built shelters for     7     (survive). Fresh water and food were taken to the city. Slowly, the city began     8     (breath) again. With strong support from the government and the tireless efforts of the city’s people,     9     new Tangshan was built upon the earthquake ruins. It has proved that in times of disaster, people must unify and show the     10     (wise) to stay positive and rebuild for a brighter future.

Earth Day is an event    1    (annual) celebrated on April 22.     2    (found) by Senator Gaylord Nelson, an American politician and environmentalist, it was originally aimed at helping the public to know the current situation of air and water pollution and    3     (get) people to care about the earth.

In1962, Rachel Carson’s bestselling book “Silent Spring” created an    4    (aware) of the dangerous effects of pesticides (农药) . Then, a fire,     5     broke out in 1969 on Cleveland’s Guyahoga River, shed light on the problem of chemical pollution in water. Senator Gaylord Nelson dreamed of    6    similar large event that would get people to take environmental issues seriously. In 1969, he was inspired by protests against the Vietnam War and came up with the idea for Earth Day.

In the fall of 1969, Nelson announced it and appealed to the entire country to get involved. Consequently, telegrams, letters and telephone calls    7    all over the country poured in. Since 1970, Earth Day celebration have grown. Later, Nelson    8    (award) the Presidential Medal of Freedom in recognition of his work.

Today, Earth Day is celebrated around the world every April 22. Sometimes numerous communities celebrate Earth Week, an entire week of    9    (activity) focused on the Environmental issues. In 2017, the March for Science    10    (occur) on Earth Day(April 22, 2017) and was followed by the People’s Climate Mobilization (April 29, 2017).

Air pollution is a killer. The World Health Organization says it kills about seven million people around the world each year. Even if    1    (pollute) air does not kill us, it can make us very sick.       2    (wear) face masks, people walk past heavy traffic as Beijing is hit by a sandstorm. The government in Beijing issued a blue warning on air pollution as sandstorms swept through the Chinese capital city.

However, breathing in dirty air    3    (frequent) may do more harm to your body,    4    can also affect your brain and your ability to think. A new study shows that air pollution can cause a huge decrease in our    5    (intelligent).The researchers reported that long term suffering air pollution can affect a person's mental abilities in two    6     (area):language and math.

The researchers studied about 25,000 people from across China. Between 2010 and 2014, these Chinese men, women and children     7    (give) language and math tests. The researchers found that breathing in     8    air which has been polluted can reduce a person's education level by about one year. The effect generally is even    9     (bad)for those over years of age, for men and for those with little or no education. The researchers noted that the effect of pollution    10     language ability is even more serious as people age, especially among men and the less educated.