题干

去年,我国部分地区爆发了H7N9禽流感.为了防止禽流感蔓延,人们将家禽捕杀、掩埋,并在禽舍和掩埋坑中洒上大量热石灰.

(1)熟石灰属于____ (填“酸”、“碱”或“盐”).用熟石灰处理硫酸厂废水中的硫酸,其化学方程式为____  .

(2)熟石灰的溶解度曲线如图所示,30℃时,将1g 熟石灰加入100g水中充分搅拌、过滤,若不计溶液损失,得到溶液的质量是____ g.将该溶液降温到20℃,是否有固体析出____,(填“是”或“否”)溶液中溶质的质量分数将____ (填序号)

A.不变B.增大C.减小.

上一题 下一题 0.0难度 选择题 更新时间:2016-08-16 03:39:09

答案(点此获取答案解析)

碱,Ca(OH)2+H2SO4=CaSO4+2H2O,100.15,否,B

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    English is full of colorful phrases to describe shyness. Someone shy might be called shrinking violet or a wallflower, while for especially nervous types we have the curious expression: they wouldn't say boo to a goose.

    None of these are traditionally seen as positive descriptions, even if you like geese. In a culture of go-getting, high achievers, shy people don't come first. Or that's what the self-help industry would have you believe. Bookshops are filled with vital tomes(巨著) that promise to help beat social fears and find success in life, love and business. That is why one book, Shrinking Violets: A Field Guide to Shyness, bucks the trend. It became a sudden success across English-language media recently for its new take-on shyness.

    Author Joe Moran says that despite struggling with shyness and longing for loneliness all his life, being shy can also be "a gift". Freed from the constant urge to participate and compete in social situations, people are liberated to look at the world in new ways, and gain fresh insights.

    Indeed, many of the world's great thinkers and artists are introverts(内向的人). Scientists Charles Darwin and Albert Einstein preferred their own company; actress Keira Knightley often finds herself tongue-tied at parties; and Harry Potter author JK Rowling claims she used to be too nervous to even borrow a pen.

    Moran told BBC Future: "I think shyness probably does turn you into an amateur anthropologist(人类学家), really-you are more likely to be an observer."

    So, while extroverts make all the noise, they don't necessarily have the best ideas.

    If you're shy, you've probably known this for a long time. You just don't shout about it.