矩形具有而平行四边形不具有的性质是（） A．对角线互相平分 B．对角线相等 C

发布时间：2017-04-22 17:42 │ 来源：www.tikuol.com

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问题：

矩形具有而平行四边形不具有的性质是（　　）

A．对角线互相平分

B．对角线相等

C．内角和为360°

D．对边平行且相等

考点：平行四边形的性质矩形，矩形的性质，矩形的判定

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       Vitamins(维生素)  are a discovery of the 20th century. A hundred years  1   , no one knew
anything   2   them. The vitamins are   3   by letters of alphabet. Vitamin A   4   by the eyes. There
is vitamin A in milk, butter and green vegetables It 5   by the body.
       Vitanun B must be supplied (提供)  6   by some of our food. The skins  7   grains of all sorts
have vitamin B in them.
       Vitamin C is very important   8_ the body. Without it   9   teeth will become loose and their
arms and legs become weak. Oranges and tomatoes 10   vitamin C in them.
       There are other vitamins.  But these A, B,C are the most important.

( )1. A. before
( )2. A. about
( )3. A. naming
( )4. A. needs
( )5. A. stores
( )6. A. times
( )7. A. of
( )8. A. in
( )9. A. people
( )10.A. has

B. front
B. of
B. named
B. need
B. be stored
B. in not time
B. to
B. at
B. peoples'
B. have

C. ago
C. in
C. is named
C. is needed
C. can store
C. all the time
C. on
C. with
C. people's
C. there is

D. ahead
D. for
D. names
D. was needed
D. can be stored
D. any times
D. in
D. to
D. peoples
D. there are

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计算(π-3)⁰=（）

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2002年诺贝尔物理学奖中的一项，是奖励美国科学家贾科尼和日本科学家小柴晶俊发现了宇宙X射线源．X射线是一种高频电磁波，若X射线在真空中的波长为λ，以h表示普朗克常量，c表示真空的光速，以E和m分别表示X射线每个光子的能量和质量，则（　　）

A．E=，m=0

B．E=，m=

C．E=，m=0

D．E=，m=

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据报道，现在有些医院已采取了一些隔离措施，使体格检查置于一个相对封闭的环境中，以免受检患者曝光于众人面前。更确切地说这些措施反映了医院和医生哪一种医德意识（）。

A.服务意识

B.管理意识

C.保护患者隐私意识

D.有利于患者的意识

E.热爱医学事业的意识

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高压开关柜外绝缘应满足的条件。

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