2 . Plastic is everywhere. A lot of it ends up in the ocean. Most plastics in the ocean break up into very small particles called “micro-plastics”—less than five millimeters in length or about the size of a sesame (芝麻) seed. It is the most common type of marine debris (垃圾) found in the ocean. Plastic debris can come in all shapes and sizes and be harmful to our ocean and water life.

Micro-plastics come from various sources, including larger plastic debris that degrades into smaller pieces. In addition, micro-beads, a type of smaller micro-plastic, are very tiny pieces of manufactured polyethylene (聚乙烯) plastic added as exfoliants (去角质剂) to health and beauty products,like toothpastes. These tiny particles easily pass through water systems and end up in the ocean, posing a potential threat to water life. What is worse, these micro-beads or plastic particles in the marine environment are eaten by plankton (浮游生物)，which are then eaten by fish. They continue to work their way up the food chain until they reach our dinner plates.

New research has shown that household dust is a more likely source of micro-plastics. According to researchers,114 pieces of micro-plastic settle on a dinner plate during the 20-minute duration of a meal. adding up to anywhere between 13,000 and 68,000pieces per year. And when you breathe in air, you could be breathing in the microscopic plastic particles as well.

How about drinking water? The non-profit journalism organization Orb Media tested 259 bottles of water bought from 9 different countries. The tests found that there was an average of 10. 4 plastic particles (0. 1 millimeters or larger) per liter of water. That level of micro-plastics in bottled water was double the level found in tap water. The findings suggest if you drink one liter of bottled water per day, you could be consuming tens of thousands of micro-plastic particles each year.

It is apparent that the problem of micro-plastics is still a huge one.

3 . The tradition of giving gifts didn’t start with the modern holidays we celebrate. Many ancient cultures celebrated holidays with the exchange of gifts. People who love to give gifts often can’t wait until it’s time for the recipients to open their gifts. If you’ve ever been given a gift, you know that part of the fun is the curiosity that builds as you wonder what the gift is.

The wish to hide the identity of a gift until just the right moment led people to wrap gifts long, long ago. Historians believed wrapping gifts in paper probably started not long after paper was invented thousands of years ago.

Wrapping paper like what we use today, though, is a much more recent invention. More than 100 years ago, gifts were usually wrapped in heavy brown paper. Before that, cloth was often used. The technology to mass-produce wrapping paper didn’t come along until the early 1900s. The first American gift wrap company— Hy-Sill Manufacturing Inc. — was founded by Eli Hyman and Morris Silverman in 1903. It wasn’t as easy to wrap presents back then as it is today, though, because adhesive tape (胶带) wasn’t invented until 1930.

Over the years, wrapping paper has developed into what we see in stores each holiday season. But scientists say that the United States alone produces an extra 5 million tons of waste over the holidays, most of which is from wrapping paper and shopping bags. To cut down on this waste, some people carefully unwrap presents, so that the wrapping paper can be reused. Others have started to use reusable gift bags instead of wrapping paper.