A teacher stood on the top of a ladder truck. It was five stories high. She held an egg that was attached(系) to several balloons and was about to drop it. The students below fixed their eyes on her and held their breath. Would the egg survive the drop?

Welcome to Kelly Coombe’s science class at Marsh Junior High in Chico, California. Coombe organized this activity to help students better understand the laws(定律) of physics.

She divided the 34 students into 17 teams of two people each. Each team designed a structure that would prevent an egg from breaking when dropped from about 15 meters high.

The students used different materials to protect the eggs. The typical materials included cotton balls, drinking straws(吸管), cardboard, socks and balloons.

Josh Addington and Bowen Jiang thought of a creative idea. They built a pyramid out of drinking straws and put the egg into a “capsule(胶囊)” on the top of the pyramid. Then they tied a helium-filled balloon(氦气球) to the top to keep the device moving in the right direction, and put a water balloon at the bottom to allow the device to lightly land on the ground. “Our egg survived!” Jiang proudly told his teacher and classmates.

Coombe said the project was a “great way for kids to get excited about science”.

When in fear, ostriches(鸵鸟) hide their heads in the sand instinctively(本能地) in the hope that trouble will pass them by. In fact, ostriches don’t hide their heads in the sand to avoid danger. Not only would they be unable to breathe, but when you think about it, they really have no reason to do so.

Ostriches are the fastest animals walking on two legs, able to run as fast as 40 miles per hour. They stand around 9 feet tall and weigh 350 pounds. If in danger, they can give a kick that is powerful enough to kill a lion. So why do ostriches bury(埋) their heads in the sand?

When it’s time to start a family, the ostrich digs a big hole that is between 6 and 8 feet wide and 2 to 3 feet deep. They bury the eggs safely in the ground, and then the mom and dad take turns sitting on the eggs to protect them until the babies are ready to come out of the eggs. A few times a day, the ostrich parents bury their heads in the ground to turn the eggs using their mouths.

When it has eggs to protect, the ostrich will run, attracting enemies to go after it. Thanks to their fast speed, ostriches are able to easily shake off the enemies, leaving their eggs and themselves free from danger.

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Paper or Plastic? _______

①Governments around the world are bringing about an end to plastic straws and bags. More and more businesses are using paper products as an alternative (替代). Paper is considered by many to be better than plastic. However, it, too, is harmful to the environment.

②Firstly, paper bags and straws are made from trees. Trees, as you know, can reduce carbon dioxide levels in the atmosphere (大气层). They can slow down climate change. An increase in the use of paper bags can cause more deforestation.

③Secondly, the production of paper items requires more energy and water. About 10 percent more energy and four times as much water is used to produce a paper bag than a plastic one. You might say that we can use recycled paper to save that energy and water. This seems to be a good idea. However, it takes even more energy and water to go through the recycling process than to make a brand new paper bag. Products made from recycled paper are also often short-lived.

④Furthermore, paper products are heavier than plastic ones. That means they require more fuel to transport. Seven trucks are needed to transport two million paper bags, while only one truck is needed to transport the same number of plastic bags. The increased weight also leads to a larger amount of waste once the bags are thrown away.

⑤Paper products are actually a lose-lose for both the environment and businesses. They are more expensive than plastic products. A paper straw costs about 5 to 12 cents, while a plastic one usually costs only about 2 cents.

⑥The most environment-friendly solution is to avoid single-use items altogether. Products like glass water bottles and steel straws can be used over and over again. They are much better than either paper products or plastic products. Through increasing the use of these items, you can greatly reduce your throwaway waste and truly make our Earth a greener place!

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