蛋白质是机体生长及修补受损组织的主要原料,人体通过食物获得的蛋白质在胃肠中与水反

题型:计算题

问题:

蛋白质是机体生长及修补受损组织的主要原料,人体通过食物获得的蛋白质在胃肠中与水反应,生成氨基酸,蛋氨酸(化学式为C4H11O2NS) 就是其中的一种。请通过计算回答下列问题:

(1)蛋氨酸中各元素的质量比m(C):m(H):m(0):m(N):m(S)为多少?

(2)蛋氨酸中,氮元素的质量分数是多少?(精确到0.1%)

(3)合格奶粉每100g中含蛋白质约18g,蛋白质中氮元素的平均质量分数为16%.则每100g合格奶粉中,氮元素质量为多少克?

考点:物质组成元素的质量分数物质组成元素的质量比
题型:计算题

Large companies need a way to reach the savings of the public at large. The same problem, on a smaller scale, faces practically every company trying to develop new products and create new jobs. There can be little hope of raising the money needed from friends and people we know, and while banks may agree to provide short-term finance, they are generally unwilling to provide money, for long-term projects. So companies turn to the public’ inviting people to lend them money, or take a share in the business in exchange for a share in future interests. This they do by issuing stocks and shares in the business through the Stock Exchange. By doing so they can put into circulation the savings of single persons and institutions, both at home and abroad.
When the saver needs his money back, he does not have to go to the company with whom he originally placed it. Instead he sells his shares through a stockbroker to some other Saver who is seeking to invest his money.
Many of the services needed both by industry and by each of us are provided by the government or by local organizations. Without hospitals, roads, electricity, telephones and railways, this country could not work. All these require continuous spending on new equipment and new development if they are to serve us properly, requiring more money than’ it is raised through taxes alone. The government, local organizations and nationalized industries therefore frequently need to borrow money to finance: major capital spending, and they, too, come to the Stock Exchange.
There is hardly a man or woman in this country whose standard of living does not depend on the ability of his or her employers to raise money to finance new development. In one way or another his new money must come from the savings of the country; The Stock Exchange exists to provide a channel through which these savings, can reach those who need finance.

The underlined word invest probably means ______.
A. give more money with
B. provide less money with
C. borrow less money with
D. make more money with

题型:计算题

引起支气管哮喘发作,释放细胞因子和炎性介质的细胞是()

A.嗜酸性粒细胞

B.肺泡巨噬细胞

C.肥大细胞

D.气道上皮细胞

E.以上都包括

题型:计算题

下列各组稀溶液,仅用同组稀溶液间的相互反应,就可以将其区别开来的是(  )

A.Na2CO3、HCl、HNO3、Na2SO4

B.K2CO3、H2SO4、HNO3、BaCl2

C.HCl、AgNO3、HNO3、NaCl

D.Na2SO4、NaOH、CuSO4、NaCl

题型:计算题

在正常操作条件下,醪液温度达到65摄氏度后,在30分钟左右糖化完全,麦芽质量为()。

A.优秀

B.良好

C.一般

D.较差

题型:计算题

太阳中喝,白虎加人参汤的主证:

A.汗出恶寒,身热而渴

B.发热无汗,口渴溲赤

C.但热无寒,渴喜冷饮

D.壮热烦渴汗出

E.发热恶寒,无汗而喘

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