【英语时差8,16】“闪闪发光”的项链（上）

If you go to any outdoor, nighttime event these days, you’re likely to see people wearing glowing plastic necklaces. These necklaces seem to glow magically, as though they were made from cool, flexible neon lights. Each necklace is a hollow, plastic tube filled with chemicals–non-toxic, of course–and those chemicals are undergoing a slow reaction to create “chemiluminescence”–or light from chemicals. This reaction is essentially¹ oxidation, the same thing as burning, but the energy released by a chemiluminescent reaction comes out as light, not heat. Indeed, the cool chemistry that takes place inside one of those glowing necklaces is very similar to the chemistry that lets fireflies glow. Here’s How It Works.You start the reaction by bending the flexible tube. This breaks a miniature glass vial inside, and allows two different chemical solutions to mix.

1 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。