2 . STA Travel, the world’s largest students and youth travel agency, beats any price! Every day we’re working with our partners around the world to get you (students, teachers and anyone under 26) the cheapest and most comfortable fights and accommodations. This part of www.statravel.com provides great tips for green travel—how to pack, how to leave your house or apartment, and how to plan for your trips. You’ll also find a great number of green travel adventure (探险) trips to all comers of the world.

Green travel means responsible travel! Leave as little influence as possible on the places you visit and protect the environment both at home and during your trip. Think “Green” when you pack and when you travel. You’ll help prevent long-term effects on the communities you leave and visit!

Before you leave

◆Turn your water heater to its lowest setting.

◆Turn off your water from the outside.

◆Pack suitable clothes in your luggage, none of which is to harm the environment.

While you travel

◆Try products made from recycled materials.

◆Don’t buy souvenirs produced from endangered species (物种).

◆Carry a reusable bottle for water and refill it as you go.

◆Use the bathroom in the airport, NOT on the plane. The fuel used for a single flush (冲洗) could run a car for six miles.

3 . Green travel is becoming more and more popular. Travelers are changing their usual holiday places through green travel. It is not only good for the earth，but also for the experience of the trip.    1    

Choose a green place.

    2    If you are one of those travelers，start by choosing a green place. Travelers should look at places that are friendly to the environment.

    3    

Travelers should know something about green hotels before they book. Some hotels host educational talks to help their guests make green choices，other hotels will use signs and brochures to educate the guests.

Use public transport，hire a bike or walk.

It may seem easy to drive a private car to see the sights，but it is not good for the environment. To reduce the carbon emissions（排放），why not use public transport？    4    ride a bike or walk.

Choose to eat local.

Many travelers want to visit local homes and taste home cooked meals. Eating locally made a good influence（影响）on a country.

Say no to plastic.

One of the biggest problems in the world is the use of plastic. Green travelers can reduce the use of plastic by taking part in clean-up activities.    5     travelers have to find practical ways of dealing with it.

4 . Bees may soon need to add protein shakes to their diet. Pollen (花粉) normally provides their protein (蛋白质). But rising levels of carbon dioxide (CO₂) in the air have reduced the protein in pollen. That’s what a new study finds.

Scientists compared recently collected flowers from Canada goldenrod. Then they compared pollen in them to pollen in goldenrod reserved at a museum in Washington, DC. They found today's plants have less protein. Protein levels in pollen from the older flowers were 18 percent. Today's goldenrod pollen has only about 12 percent protein. That's about one-third less than 172 years ago. Over that same period, CO₂ levels have gone up by more than one-third. Back more than 170 years ago, they were about 280 parts per million in air. Today they are about 398 ppm.

To test whether CO₂ changes had played a role in the falling protein levels, the researchers did some tests. They grew goldenrod for two years at CO₂ levels of up to 500 ppm. More CO₂ in the air led to lower levels of protein in the flowers’ pollen.

Joan Edwards, one of the researchers, says that this drop in pollen protein could affect a bee’s diet and health. It would be like eating junk food, tasting good but offering less nutrition (营养).

Honeybees need to eat lots of protein. They use it to feed their young. They also need it to keep their immune systems healthy, says Cédric Alaux, a bee biologist at the French agricultural research agency.

Bee populations have been decreasing worldwide in recent years. A drop in their food quality might play a role, Edwards says. And that drop might affect crops too. “The health of the bee population is not just for the flowers and the bees and biodiversity.” She worries it also could play a role in “human health and well-being.”

5 . Steven Stein likes to follow garbage trucks. His strange habit makes sense when you consider that he’s an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road. What is even more interesting is that one of Stein’s jobs is defending an industry behind the plastic shopping bags.

Americans use more than 100 billion thin film plastic bags every year. So many end up in tree branches or along highways that a growing number of cities do not allow them at checkouts(收银台). The bags are prohibited in some 90 cities in California, including Los Angeles. Eyeing these headwinds, plastic-bag makers are hiring scientists like Stein to make the case that their products are not as bad for the planet as most people assume.

Among the bag makers’ argument: many cities with bans still allow shoppers to purchase paper bags, which are easily recycled but require more energy to produce and transport. And while plastic bags may be ugly to look at, they represent a small percentage of all garbage on the ground today.

The industry has also taken aim at the product that has appeared as its replacement: reusable shopping bags. The stronger a reusable bag is, the longer its life and the more plastic-bag use it cancels out. However, longer-lasting reusable bags often require more energy to make. One study found that a cotton bag must be used at least 131 times to be better for the planet than plastic.

Environmentalists don’t dispute(质疑) these points. They hope paper bags will be banned someday too and want shoppers to use the same reusable bags for years.