Do you know of anyone who uses the truth to deceive(欺骗)? When someone tells you something that is true, but leaves out important information that should be included, he can give you a false picture．

    For example, someone might say, “I just won a hundred dollars on the lottery(彩票). It was great. I took that dollar ticket back to the store and turned it in for one hundred dollars!”

    This guy is a winner, right? Maybe, maybe not. We then discover that he bought $ 200 worth of tickets, and only one was a winner. He's really a big loser!

    He didn't say anything that was false, but he left out important information on purpose. That's called a half-truth. Half truths are not technically lies, but they are just as dishonest.

    Some officers often use this trick. Let's say that during Governor Smith's last term, her state lost one million jobs and gained three million jobs. Then she tries another term. One of the persons who don't support her says, “During Governor Smith's term, the state lost one million jobs!” That's true. However, an honest statement would have been, “During Governor Smith's term, the state had a net gain of two million jobs.''

    Advertisers will sometimes use half—truths. It's against the law to make false statements so they try to mislead you with the truth. An advertisement might say, “Nine out of ten doctors advised their patients to take Yucky Pills to cure toothache. ”It fails to mention that they only asked ten doctors and nine of them work for the Yucky Company.

    This kind of thing happens too often. It's a sad fact of life: Lies are lies, and sometimes the truth can lie as well.

    How much do you know about air pollution? When people talk about air pollution, they usually think about outdoor air 1. But do you know that there is also 2 pollution inside homes, offices, hotels and other buildings? The air in your home can be 2 to 100 times more polluted than the air outdoors! In fact, some American doctors say that 50％ of illnesses have something to do with 3 indoor air.

    A lot of pollution comes from 4 activities such as smoking and cooking. As most people 5 about 80％-90％of their time inside buildings, it is important to take indoor air pollution seriously too.

    Air pollution influences our health in many ways. When the air is polluted, not only 6 children and old people suffer from it, but people with 7 problems suffer as well. Indoor air pollution can 8 people's eyes, noses and throats. Air pollution, both indoor and outdoor, can also lead to lung cancer and heart disease! In the Great Smog of London in 1952, 4,000 9 died in a few days because of the pollution! It is 10 that half a million young children and women die each year in India because of indoor air pollution!

    Imagine a world with no more animals: no elephants, no tigers or lions. To some people, that thought is too terrible for words. So they are doing something about it. Tiffany Soechting is one of them.

    Being among wild animals—feeding them and caring for them—is all Tiffany Soechting has wanted to do with her life. And that is exactly what she does!

    Soechting is the human "mother" to the 500 animals that live on her family wildlife farm in San Antonio, Texas. On the farm, she cares for animals from around the world. Soechting says she loves them all. However, two reticulated giraffes(网纹长颈鹿) take up a special place in her heart. Their population in the wild has become smaller by 80% in the last 15 years. "I'm so glad to get help from five wildlife researchers that took giraffes up to a higher level. All our hard work helps protect giraffes living in the wild."

    Besides her animal caring, Soechting also holds monthly classes, where she teaches school children about the animals.

    Soechting also opens the farm to the public. Visitors not only learn about the animals, they can also get close to them. And the animals are not against that. For them, people are part of their natural environment.

The farm is part conservation(保护) area, part educational center and part animal park. As the animals walk peacefully around the grounds, it is easy for them to forget that San Antonio, a busy city, is just a few minutes away.

    All week long, it seems you sit inside at school when it is fine outside. But when the weekend comes, it is very cloudy. There is rain according to(根据) the weather report.

    Scientists studied more than 40 years of weather data(数据) from around the world. It shows weekend weather is different from weekday weather in some places.

    Part of the study involved(包括) 660 weather stations in the US. At more than 230 of these places, the weather on Saturday, Sunday and Monday was different from the weather on Wednesday, Thursday and Friday. The difference was small, but the pattern was striking enough to make the scientists take notice.

    "This kind of weekly rise and fall doesn't line up with any natural cycles, "the scientists say. Instead, they think that air pollution from human activities makes the weather become different.