含硒（Se）的保健品已开始进入市场。已知硒与氧、硫同主族，与溴同周期，则下列关于

发布时间：2017-06-06 13:54 │ 来源：www.tikuol.com

题型：选择题

问题：

含硒（Se）的保健品已开始进入市场。已知硒与氧、硫同主族，与溴同周期，则下列关于硒的叙述中，正确的是

A．非金属性比硫强

B．氢化物比HBr稳定

C．原子序数为34

D．最高价氧化物的水化物显碱性

考点：构成物质的粒子—分子、原子、离子元素周期律

题型：选择题

从下面方框中选择适当的选项填入短文中，使短文通顺、完整。选项中有两个选项是多余选项。

A. dead B. understood C. until D. gold E. other F. some
G. nothing H. died I. more J. hidden K. for L. where

       There was once a hard-working farmer who had a fine olive orchard  (橄榄果园).But his three sons hated farm work.
       When the farmer was dying, he called the three sons to him and said,  "My sons. there is a pot of gold hidden in the olive orchard.  Dig    1   it,  if you want it. "
       The sons tried to get him to tell them in what part of the orchard the gold was   2   ; but he would tell
them nothing more.
       After the farmer   3  , the sons went to work to find the pot of gold.  Since they did not know   4   the hiding-place was,  they agreed to begin in a line,  at one end of the orchard, and to dig   5   one of them
should find the money.
       They dug until they had turned up the soil (土) from one end of the orchard to the   6  . But no pot
of gold was to be found.  The three sons were very disappointed(失望的) to have done all their work
for   7  .
       The next olive season, the olive trees in the orchard bore   8   fruit than they had ever given: when it
was sold, it gave the sons a whole pot of    9  .   When they saw how much money had come from the
orchard, they suddenly    10   what the smart father had meant.

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题型：选择题

主要引起成人腹泻的轮状病毒是（）

A.C组人RV

B.A组人RV

C.E组人RV

D.B组人RV

E.D组人RV

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题型：选择题

一般情况下，能使投资项目的净现值小于零的折现率，一定小于该项目的内部收益率。 ( )

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题型：选择题

新生儿出血可用（）

A．缩宫素

B．干扰素

C．鱼精蛋白

D．麦角胺

E．维生素K

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题型：选择题

电动空气压缩机润滑油更换。压缩机运转150h后进行1次初期换润滑油，每运行（）km或每24个月进行1次定期更换润滑油。

A.20万

B.40万

C.60万

D.80万

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