People usually check whether their keys, wallets and phones are with them before going out. But many people in China now have one more important thing to take, a face mask. They hope that it can protect them from the polluted air.

Since January, many cities in China have seen a lot of hazy days. During these days, people can only see things that are very near them. In Beijing, only five days in January were free of smog.
According to the Chinese Academy of Sciences, driving cars and burning coal are two major factors for PM2.5, which is the main problem with air pollution. Poor air is bad for people’s health, especially for children and the elderly. Air problems and environmental protection have become a concern for the whole nation.
Our government is taking action to prevent pollution and give people a healthy living environment. It calls on people to make full use of energy and resources and cut down on energy use.
People will take 　　 with them before going out, hoping to protect them from the polluted air.

A．keys

B．wallets

C．phones

D．face masks

What does the underline word mean?

A．阴雨的

B．阳光明媚的

C．雾蒙蒙的

D．月光下的

What are the main factors for PM2.5 according to the Chinese Academy of Sciences?

A．driving cars and having fewer trees

B．burning coal and having fewer trees

C．having fewer trees and no rain

D．driving cars and burning coal

Why do the air problems and environmental protection become a concern for the whole nation?

A．Because people can’t see things clearly.

B．Because there are many hazy days.

C．Because the poor air is bad for people’s health.

D．Because there are so many cars in China.

What can people do to prevent pollution?

A．use less coal than now

B．cut down on energy use

C．use less resources

D．reduce and make full use of energy and resources