Many people regard summer as a time for relaxing, eating ice cream, and...ouch! I just got bitten by a mosquito!　
For centuries, people have been searching for effective ways to prevent mosquito bites. What they have been looking for is mosquito repellent1. This refers to anything that keeps mosquitoes away or prevents them from landing on you. Mosquitoes have always been hard to deal with. Therefore, it is not surprising that the origins of mosquito repellant are from long ago.
　
The first known mosquito repellent was used by ancient Egyptians. They took oil from castor oil plants2 and burned it in lamps. Ancient Romans used a mix of vinegar3, resin4, and oil to drive away insects that bite. Many other cultures, such as those in India and China, also used plants as repellents. Around 1890, the first mosquito coil5 was made in Japan. It was made of natural plant oil. Today, these coils are used all over the world. During World War II, the first chemical repellents were created. In 1946, the American government developed DEET. Since then, it has been the chemical that is most often
added to repellents.
　　
許多人把夏季視為是悠閒放鬆、吃冰淇淋的好時光，還有……噢！我剛被蚊子叮了一下！
　　
數百年來，人們一直在尋找預防蚊子叮咬的有效方法。他們所尋尋覓覓的就是驅蟲劑。驅蟲劑指的是任何能趕走蚊子，或是防止牠們停在您身上的東西。蚊子自古以來一直都很難纏。因此，驅蟲劑的起源悠久實不令人意外。
　　
第一個為人所知的驅蟲劑是由古埃及人所使用的。他們自蓖麻中提煉蓖麻子油，並放在油燈裡燒。古羅馬人則用醋、樹脂和油的混合液來驅除會叮人的昆蟲。在印度和中國等其它文化當中，也使用植物來作為驅蟲劑。1890年前後，日本製造了第一個圈狀蚊香。它是由天然植物油所製成。如今，世界各地仍使用這種蚊香。第二次世界大戰期間，第一批化學驅蟲劑問世。1946年，美國政府研發了DEET。從那時起，它便成為最常被添加在驅蟲劑裡的化學物質。

► effective　a. 有效的
These pills are effective in curing headaches.
這些藥丸能有效治療頭痛。

1. regard A as B　　把 A 看作 B，認為 A 是 B
Chris regards Mandy as his true love.
克里斯視曼蒂為他的真愛。
2. refer to...　　指的是……
I wasn't referring to you when I made my comments.
當我發表我的意見時，我指的人不是你。
3. deal with...　　解決∕處理……
Kyle had to deal with the problem by himself.
凱爾必須自行解決這個問題。
4. drive away.../drive...away　　趕走……
Mom used a broom to drive the rat away.
媽媽用掃帚把老鼠趕跑。
5. be made of...　　由……製成
This dessert is made of bananas, chocolate, and ice cream.
這道甜點是由香蕉，巧克力和冰淇淋所製成。