Human beings and cats are believed to be friends. They     1     together for about 9,500 years. As cat owners know well, cats do not follow humans’ order in the same way dogs do. Lots of cats love having cat companions, but if yours doesn’t, it might act out by showing fear or     2    .

“This doesn’t     3     mean you have to give your pet up! ―Cats are good learners,” says Kristyn Vitale, a     4     at the Human-Animal Interaction Lab at Oregon State University, US. She suggests     5     the cats into different areas of the house and people should slowly introduce them to one another using a method     6    —Smell, See, Touch: Take a toy from each cat and exchange them.

Give each cat the other cat’s toy along with lots of praise and rewards so they connect the smell with good things. After doing this a few times, set up a space     7     the cats will be able to see one another through a physical barrier,     8     a glass door or gate. Then feed them, so they start to connect positive feelings (food) with the sight of the other cat. After a few     9     feeding times, you can try to introduce the cats without a barrier—keep each cat with toys during their first meeting in the same room, so they have less time     10    .

—If owners go slow and give lots of rewards, many cats can learn to accept a companion cat, Vitale says.

The pollution of the earth’s soil and water has become an issue of great concern. Until recently, most of that     1     has focused on the land     2     of the planet, where pollution directly affects people in their daily lives. Now, however, we have begun to realize that marine (海洋的) pollution is     3     important. According to S.A. Patin, marine pollution is the condition that results when people introduce into the seas substances harmful to life, health, resources, activities, or     4    .

Marine pollution is far from new. For over a million years, people have thought of the sea as a     5     place to throw their garbage. And it is true that the sea has a great capacity for absorbing organic wastes. Some of these wastes are eaten directly by the larger fishes. Others quickly     6     into a kind of organic soup that provides food to     7     species of single-celled plant and animal life.

As civilizations grew, more different pollutants were dumped into the seas. Still, this pollution did not really threaten the marine environment. The seas seemed     8     of coping with anything that people could throw at them. This situation changed, however, when suddenly factories began dumping enormous quantities of materials into the seas. Especially in some coastal areas near large cities, ocean pollution began to     9     marine life. For the first time, the oceans began to fail in their ability to     10     humanity’s waste.

As you may know, coral (珊瑚) is not a plant, but an animal. However, coral reefs (珊瑚礁) around the world are in    1    . Here is a piece of bad news. Thailand will close one of its beaches to protect its coral       2     business activities for tourists. The beach is so famous that     3    of tourists put it on their wish lists. More than 5,000 visitors visit it a day. They arrive by boat. This does    4     harm to the coral reefs. Most of the coral has died. The beach will be closed between June and September to let the coral come    5    to life．

Experts (专家) say that 80％of Thailand’s coral reefs have been    6    . Too many tourists     7     a lot of pollution to these beaches. An expert said the biggest problems were hotels by the beaches, boats, and plastic waste in the sea. He believed the     8    choice was to close the beaches forever. He said, “I hope the       9       can take steps to protect the coral reefs. At the same time, I also hope all of us should    10    our best to protect the environment around us.”