科普園地
Sunny days may seem like the perfect weather to have fun outside. Many people enjoy cycling in the park, hiking in the mountains, and swimming at the beach. However, there is something one should always do before heading outdoors to enjoy these activities—put on sunscreen.
Sunscreen is composed of particles that physically bounce radiation off the skin and react with ultraviolet (UV) rays, absorbing the rays and giving off the energy as heat. While there are no sunscreens that can give you 100% protection from the sun, they can greatly reduce the effects of sun damage.
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Labeled on every bottle of sunscreen is its sun protection factor, or SPF. This number measures the protectiveness of the sunscreen against UV radiation. For example, a sunscreen that offers an SPF of 30 will block around 97% of the UV rays. Comparatively, a sunscreen containing an SPF of 50 will shield against 98% of the UV rays. Selecting a sunscreen with an adequate SPF is important for effective protection; otherwise, too many of the sun’s harmful rays will penetrate the sunscreen.
When you choose the right sunscreen, it’s useful to think about the activities you will be doing.Sunscreen is only effective for a certain amount of time. Sweating and doing things like swimming will decrease the duration of its effectiveness. Therefore, it is wise to apply waterproof or water-resistant sunscreen to your skin. It is also important to note that there are two types of UV radiation: ultraviolet A (UVA) and ultraviolet B (UVB) rays. Both of these rays can cause sunburn and skin cancer; however, most sunscreens only provide protection from UVB rays. So, when purchasing sunscreen, try looking for kinds that help protect your skin against both UVB and UVA.
答案: 1. D 2. A 3. C
Oxygen reacts with hydrogen to produce two compounds: water and hydrogen peroxide.
氧氣和氫氣反應後會產生兩種化合物:水及過氧化氫。
The sun gives off light and heat.
太陽會散發光與熱。
Students will learn how to apply this theory to real-life situations.
學生將學習如何將這理論應用於實際生活情境中。
Apply this cream to your wound three times a day.
每天將這藥膏塗在傷口上 3 次。
This lotion will protect your skin against ultraviolet rays.
這種乳液會保護你的肌膚對抗紫外線。
shield [ ˋʃild ] vi & vt. 防護,遮蔽
• The ozone layer shields the Earth from the sun’s ultraviolet rays.
臭氧層保護地球免受太陽的紫外線所害。
以下介紹有表「保護」意味的單字:
a. protect [ prəˋtɛkt ] vt. 保護,防護
• This thick sweater will protect you from the cold.
這件厚毛衣可以讓你禦寒。
b. guard [ gɑrd ] vt. 保衛,守衛
• The secret service agents guarded the president closely as he shook hands with voters.
那些特勤人員在該總統和選民握手時,嚴密保護他的安全。
c. safeguard [ ˋsef͵gɑrd ] vt. 保護,保障;防衛
• This agreement will safeguard the consumers from being exploited.
這項協定將保障消費者免遭剝削。
d. preserve [ prɪˋzɝv ] vt. 保護,保存(強調東西保持原樣)
• The scientists have been trying their best to preserve the natural habitat of the panda bear.
科學家們一直在盡全力保護貓熊的自然棲息地。
e. harbor [ ˋhɑrbɚ ] vt. 包庇,窩藏
• The man was accused of harboring a murderer for several days.
該男子被指控窩藏殺人犯好幾天。
防晒乳 : 抗晒的第一道防線
陽光明媚的日子似乎是在戶外玩樂的完美天氣。許多人喜歡在公園騎自行車、在山上健行、在海邊游泳。但在前往戶外享受這些活動之前應該都要做某件事 ─ 塗防晒乳。
防晒乳由粒子組成,這些粒子以物理方式從皮膚反射輻射並與紫外線發生反應,吸收光線並以熱量的形式釋放能量。雖然沒有防晒乳能給你百分之百的防晒保護,但它們可以大大減少皮膚損傷的影響。
每瓶防晒乳上都標有其防晒係數(SPF)。這個數字計量出防晒乳對紫外線輻射的防護力。例如,防晒係數為 30 的防晒乳可以阻擋大約 97% 的紫外線。相比之下,防晒係數 50 的防晒乳可以隔絕 98% 的紫外線。選擇具有足夠防晒係數的防晒乳對於有效保護很重要;否則過多的太陽有害射線會穿透防晒乳。
當你在選擇合適的防晒乳時,考慮一下你將要進行的活動會很有用。防晒乳只在一段時間內有效。出汗與進行游泳等活動會縮短其有效時間。因此,明智的做法是在皮膚上塗抹防水或抗水的防晒乳。有一點很重要、務必留意的是, 有兩種類型的紫外線輻射:紫外線 A(UVA)和紫外線 B (UVB)射線。這兩種射線都會導致晒傷和皮膚癌;然而, 大多數防晒乳僅提供對 UVB 射線的保護。因此,在購買防晒乳時,試著尋找有助於保護你的皮膚同時抵禦 UVB 和 UVA 的那種防晒乳吧。
1. 下列哪項敘述是正確的?
(A) 大多數防晒乳可以防止 UVA 射線。
(B) 防晒乳可以完全阻擋太陽光線。
(C) 所有的防晒乳都適合游泳和流汗的時候用。
(D) 防晒係數是防晒乳能多有效地保護皮膚免受某種射線傷害的指標。
2. 艾咪和她的三個朋友一起去藥妝店買防晒乳。他們 對防晒乳瓶子上看到的東西所做的解讀哪一項是正確的?
(A) 朋友 1:「大多數種類的防晒乳僅提供對 UVB 射線而非 UVA 射線的防護。」
(B) 朋友 2:「瓶子上的數字表示它的有效性可以持續五十個小時。」
(C) 朋友 3:「防晒係數為 50 的防晒乳只能保護我們免受 50% 的紫外線傷害。」
(D) 艾咪:「它是防水的!我們只要去海裡玩之前塗一次就好。」
3. 根據本文,紫外線照射過多有什麼影響?
(A) 皮膚修復和皮膚癌。
(B) 晒傷和極度口渴。
(C) 皮膚癌和晒傷。
(D) 出汗和晒傷。