Since my mother moved to live with us in the city, she has been much heavier than before. As time went by, her health got _______. So I had to take her to see a _______. My mother was told to lose weight by doing exercise every day. She had no choice but to follow _______ the doctor said. I told her that I would exercise with her every morning.

On the first morning, she got up very early and ran with me in our neighborhood. I tried to run _______ so that she could follow me. After _______ for some minutes, I told her the proper ways of exercise and the importance of eating healthy food. She listened to me carefully. It made me _______ that she told me everything very patiently when I was a kid. On the second morning, I praised her for keeping running with me.

But after two weeks, she wanted to _______ running because she thought the two-week exercise didn't work at all. To encourage her, I taught her how to use the facilities (设施) for exercise in our _______. She began to exercise again.

With my help, it _______ her one month to develop a good habit of daily exercise. "Thank you, my dear daughter. Exercise brings health and happiness to me. I will ________ worry about my health." Her words touched my heart deeply. I felt happy to make a big difference to my mother's life.

For at least 3,000 years, the Chinese have written stories and poems out giant pandas. Ancient writings say that emperors kept these pandas as a sign of wealth (财富). A giant panda's skull (头盖骨) was found in the tomb of an empress who lived over 2,000 years ago. Skins and bones of pandas have been discovered in older tombs as well. Today pandas are China's national symbol of peace and friendship, they are usually sent to other countries as popular presents.

All the forests of southern and eastern China were once the home of pandas. Now they live in the south-central mountains of Sichuan, Shanxi, and Gansu Provinces. The Chinese government has set up nature reserves in these mountains to protect pandas and other species of plants and animals.

Giant pandas have been known to spend up to 16 hours a day eating. They eat 30 to 40 pounds of food in one day! The reason why pandas eat so much is that bamboo doesn't have many nutrients (营养物). They need to consume (消耗) a lot. Bamboo is also hard to digest (消化) and passes through their bodies very quickly.

Pandas in the wild might live for 20 years. Pandas live longer in zoos. Hsing Hsing was 28 when he died at the Smithsonian National Zoo. In China, pandas in zoos have lived to be even older.

Mars (火星) is a planet. It is the fourth planet from the sun and is more than 200 million kilometers from it. That is a very long way. Mars is also a very long way away from the earth but sometimes you can see it clearly at night. Most stars are white. Mars is a bit red.

It is not a very big planet. It is about half the size of the earth. The earth has one moon. Mars has two moons. They are called Photos and Deimos.

Long ago, the only way to study Mars was just to look at it. People with good eyes could see me things but not everything.

Later on, it was easier, because scientists had telescopes. They could see Mars more clearly. They learned much more about Mars this way.

In the 20th century things got even better. First of all, we had spacecraft (宇宙飞船).They flew close to Mars and sent back information. Then, they sent spacecraft to fly in orbit (轨道) around Mars. Finally, spacecraft landed on Mars. Maybe one day a man will walk on Mars.

A man named Jamie works for NASA with the team sending a spacecraft to Mars. "We landed a rover (探测车) on Mars" he says. "It is called Curiosity."

What is a rover? It is a machine that looks like a car. It can move about on Mars. It has cameras to take photos and it sends them back to the earth. It can study the rocks and air of Mars. It sends all this information back to the earth.