廣泛的托福閱讀背景知識積累，有助于新托福閱讀速度和準確率的提升。托福閱讀題材分為自然科學、人文科學、互聯網等幾大類，如果同學們平時能對這些種類的文章都有所涉獵，托福閱讀考試中遇到相關的話題就會有非常熟悉的感覺。下面推薦一關于水星介紹的相關背景資料，希望能幫大家積累更多的托福閱讀材料。
　　水星 (Mercury )，中國古代稱為辰星。是太陽系中的類地行星，其主要由石質和鐵質構成，密度較高。自轉周期很長為58.65天，自轉方向和公轉方向相同，水星在88個地球日里就能繞太陽一周,平均速度47.89千米,是太陽系中運動最快的行星。無衛星環繞。它是八大行星中是最小的行星，也是離太陽最近的行星。水星在直徑上小于木衛三和土衛六，水星上的太陽看上去要比在地球上大二倍半，太陽光比地球赤道的陽光還要強六倍。水星朝向太陽的一面，溫度非常高，可達到400℃以上。這樣熱的地方，就連錫和鉛都會熔化，何況水呢。 但背向太陽的一面，長期不見陽光，溫度非常低，達到-173℃，在這里也不可能有液態的水。1974年3月、9月和1975年3月，美國發射的“水手10號”探測了水星，向地面發回5000多張照片。水星地貌酷似月球，大小不一的環形山，還有輻射紋、平原、裂谷、盆地等地形。水星是太陽系中僅次于地球，密度第二大的天體。
　　Ever wonder what it's like on other planets? On this Moment of Science, find out what it's like on Mercury.
　　The great astronomer(天文學家) Carl Sagan used to say that if he were transported anywhere in the solar system he would know which planet he was on just by looking around. In this spirit of knowing your neighborhood, here's something we call . . . What's It Like There?
　　Today we ask: What's it like . . . on Mercury?
　　You're standing at the equator(赤道) on Mercury just before sunrise. We'd better put you in a protective shelter, because it's mighty(很，非常) cold–something around three hundred degrees below zero, Fahrenheit(華氏溫度計的). That's cold enough to freeze methane(甲烷，沼氣).
　　But things are looking up–by midmorning(上午中段時間，上午十點左右) it should be a (1)balmy(溫和的) eighty degrees outside. Of course, because of its rotation(自轉) and orbit(公轉), midmorning on Mercury comes twenty Earth days later, so you have a long wait.
　　When it finally arrives, though, you step outside in a protective suit and (2)bounce(跳) around in the low gravity. The ground is rocky and covered in craters(火山口). There's no atmosphere at all, so the sky overhead(在頭頂上) is black, even though the sun is perfectly visible.
　　In fact, the sun is far bigger, and brighter, than you've ever seen it on Earth–imagine a sun eleven times as bright! Not only that, the temperature is still climbing(上升的). By high noon it will be up to eight hundred degrees Fahrenheit, hot enough to melt zinc(鋅). Clearly this is no place for humans.
　　Every Mercurial day, which lasts one hundred and seventy six Earth days, the planet undergoes the same unbelievable temperature fluctuation(溫度波動) from super-cold to super-hot. Makes you glad to have a nice, temperate planet like Earth to come back to.
　　NOTES:
　　(1)balmy
　　adj. 芳香的;溫和的;止痛的
　　1.A balmy breeze was blowing across the beautiful lake.
　　一陣柔和的微風輕吹過那美麗的湖面。
　　2.Love is balmy wind that soothes pain and anxiety from the tempests of the life.
　　愛是一絲溫暖的微風，它能化解繁亂生活中梅花鹿焦慮和傷痛。
　　(2)bounce
　　n. 跳;彈力;活力
　　vt. 彈跳;使彈起
　　vi. 彈跳;彈起，反跳;彈回
　　1.The ball bounced off the wall and he caught it.
　　球從墻上彈回來，他接住了球。
　　2.Success is how high you bounce when you hit bottom.
　　成功就是在你落到底時你你能跳起多高。