In recent years，campus security have become a hot topic. In Safety Education Day，I was honored to be a volunteer raise the primary school students' awareness of safety. I told those students about things what they should never do. For an example，don't fly a kite near electrical wires or play with fire-fighting equipments. While in school，never run up and down the stairs. In addition, clean windows without any means of protection is also dangerously. I hoped these tips will help they avoid danger.

2. 只允许修改10处，多者（从第11处起）不计分。

Has anybody ever told you that you shouldn't sneeze（打喷嚏）with your eyes open and your eyeballs will pop out？This might sound reasonable，because our eyelids（眼皮）always close when we sneeze. But is that true？

Actually，this is highly likely. Although a sneeze can burst from your nose in a speed of 320 kilometers per hour，it can't transfer（转移）that pressure to your eyes. Plus，there's no muscle directly behind the eye what could push the eyeballs outward. Thus，your eyelids don't have much muscle power，so even if they are responsible for keeping your eyeballs in place，they would fail.

But then why do we always close our eyes when we sneeze？It's simple a reflex（反射）of the body，just like how our legs kick when our knees tapped. The nose and eyes are linked by nerves. so the stimulation（刺激）from the sneeze travel up one nerve to the brain then down another nerve to the eyelids，cause a blink（眨眼）for most people. It's just an involuntary reaction with no real purpose.

2.只允许修改10处，多者（从第11处起）不计分。

Within a few month, we are going to have a new set of banknotes. These bills will have new security features, that will make printing fake money even harder .

We’ve been using banknotes for around 1,000 years. Back in the Northern Song Dynasty, the world’s earliest paper money naming jiaozi was made by Chinese people. Obvious, paper money is cheaper to make and easy to carry than metal coins. But now, in the digital age, paper money seemed to be disappearing. From supermarkets to street stalls (小摊) , people pay by use the Wechat Wallet and Alipay apps on your phones. But some say it may be take a little longer than you think see paper money go away.