Which animal do you think is "the king of the animals", the elephant, the lion or the tiger? They are all large and strong. But I think the tiger is "the king of the animals". If you watch carefully, you can find some black lines on the tiger's forehead(前额). The lines look like the Chinese word "WANG". The word means "the king of the world" in Chinese.
   Most of the tigers come from China and India. Tigers are dangerous animals. They look scary(吓人的). They like eating meat. They have yellow fur with black lines. They usually weigh about 200 to 300kg. Tigers can run fast. They run at a speed of 20 meters per second.
Some people think they are dangerous. But they don't know tigers are in danger now. There are only 20 to 30 wild South China Tigers in China and less than 300 in the world. Lots of people kill them for their fur. We should take action to protect them.

    If you visit the animal shelter in Salinas, California, you'll see huge wood cutouts(剪下的图形) of a dog and a cat. These signs were placed in front of the building to catch people's attention. The supersized cut outs make people curious and encourage them to visit the shelter— and maybe even adopt(收养) a pet. Each year, the Salinas shelter takes in around 2,000 dogs and 2,000 cats. The animals are either strays or are dropped off by people who couldn't take care of them. Of the 4,000 animals, some of them are finally adopted into new homes. Some animals are moved to other shelters. And, unluckily, some cannot be saved because they are too sick or are considered dangerous.   

   Animal shelters provide food, medicine, and a safe place for animals to sleep. But they are not ideal homes. The shelters are loud, and the animals stay in small cages. The people who work at shelters do their best to care for the animals, but the animals do not always get the attention or exercise they need.  

   To prevent so many animals from becoming homeless, pet owners should take care of their pets. One of the best ways to care for pets is to spray or neuter them. This surgery prevents cats and dogs from having more babies. And that reduces the number of homeless animals that end up in shelters.

注意：(1)词数80-100，开头和结尾已给出，不计入总词数；(2)包含所给要点，可适当发挥，以使行文连贯；(3)邮件中不得出现真实姓名及学校名称。

Dear Jack,

I'm glad to hear from you. Thank you for telling me about your problem. 

Yours,

Li Hua

Every year，TIME magazine puts out its list of best inventions. They change how we live，work

Did you know that humans aren't the only species (物种) that use language? Bees communicate by dancing. Whales talk to each other by singing. And some apes talk to humans by using American Sign Language. 

A female gorilla(大猩猩), Koko, was born at the San Francisco Zoo on July 4th, 1971. Koko learned sign language from her trainer, Dr. Penny Patterson. Patterson began teaching sign language to Koko in 1972, when Koko was one year old. Koko must have been a good student, because two years later she moved onto the Stanford University campus with Dr. Patterson. Koko continued to learn on the campus until 1976. That's when she began living full﹣time with Patterson's group, the Gorilla Foundation. Patterson and Koko's relationship has been very close ever since. 

Dr. Patterson says that Koko has mastered sign language and known over 1,000 words, and that Koko makes up new words. For example, Koko didn't know the sign for ring, so she signed the words finger and bracelet(手镯). Dr. Patterson thinks that this shows meaningful and constructive use of language. 

Not everyone agrees with Dr. Patterson. Some argue that apes(类人猿) like Koko do not understand the meaning of what they are doing. Some people who don't believe that say that these apes are just performing complex tricks (戏法). For example, if Koko points to an apple and signs red or apple, Dr. Patterson will give her an apple. They argue that Koko does not really know what the sign apple means. She only knows that that if she makes the right movement, one which Dr. Patterson has shown her, then she gets an apple. The argument is not solved, but one thing is for certain: Koko is an extraordinary ape. 

It seems like Patterson and Koko have a good relationship, but not everyone agrees with it. Some people believe that Patterson is humanizing the ape. They think that apes should be left in the most natural state possible. Even Dr. Patterson struggles with these feelings. When she was asked if her findings could be duplicated by another group of scientists, she said, "We don't think that it would be ethical (道德的) to do again. " She went on to argue that animals should not be kept in such unnatural environment. 

As for the future, Dr. Patterson and the Gorilla Foundation would love to get Koko to an ape preserve (保护区) in Maui, but they are having trouble getting the land. So unless you have a few million dollars to give, Koko's going to be spending her time in Woodland, California with Dr. Patterson. Koko probably doesn't mind that. If she moved to Hawaii, she'd have to give up her Facebook page and Twitter feed, and she's got like 50 thousand "likes". Some may deny (否认) that she knows sign language, but nobody says that she doesn't know social networking.

The Maya (玛雅) number system(体系) appeared in the fourth century, which was about 1,000 years earlier than the time when the European number system was created. It is different from the Arabic number system with a base 10 (十进制). The Mayan system had a base 20. This system is believed to have been used because the Mayans lived in such a warm area and there was hardly a need to wear shoes, 20 was the total number of fingers and toes, so the system was workable. Therefore, there were two important numbers in this system. Besides 20, the other important number is 5, which had a connection with the number of fingers and toes on one hand or foot.

 The Mayan system used two symbols (符号). A dot (.) was used to mean the units ( one to four) and a dash (—) meant five. The Mayans were also the first to create symbols of nothing ( or zero). The most common symbol was that of a shell but there were several other symbols. It is interesting to learn that with all of the great experts on Maths and scientists in ancient Greece and Rome, it was the Mayan Indians who came up with this symbol zero or nothing. The following picture is a form of different numbers and how they would have been written.

 From further study, people found that the 360 day calendar(日历) also came from the Mayan. They actually used base 18 when they made the calendar. Each month included 20 days with 18 months in a year. This left five days at the end of the year which was month in itself, full of danger and bad luck. In this way, the Mayans had invented the 365 day calendar.