骨样骨瘤的临床特点 A．男：女为3：1 B．疼痛为主，尤以夜间疼痛剧烈 C．发病率依

发酵充分利用了微生物的的特点有

①代谢能力强②种类多③繁殖速度快④代谢方式多样⑤生物圈中

[      ]

A．①②③　　　　

B．①②④　　　　

C．②③④　　　　

D．①②③④

在测量电源的电动势E以及内阻r（电动势约2V,内阻约0．5Ω）实验中，给出如下器材：量程为1V的电压表，量程为0．5A的电流表（内阻较小），定值电阻Ro = 1．6Ω,滑动变阻器R,开关S,导线若干。

（1）四位同学设计了如上四个电路，实验电路应选为（   ）

（2）实验时当电流表的示数为I₁时，电压表示数为U₁;当电流表的示数为I₂时，电压表示数为U₂,则可求出电动势E的字母表达式为_____,  内电阻r的字母表达式为_______

（3）根据测量实验记录数据画出了电压表示数U随电流I的变化关系U—I图象，如图所示，由此可

知电源电动势E=_____、内阻为r=______。（结果在小数点后保留两位小数）

阅读理解

     Flags have existed for over 3000 years. The earliest flags were wooden or metal poles topped with

a carving(雕刻品). About 2000 years ago pieces of fabric were added to some poles for decoration.

Over the next 500 years the free-flying part of the flag became more important.

     Every country today has its own flag. Many groups and organizations also have a flag which stands

for, or symbolizes, the aims of the group.

     The UN flag depicts (描绘)a world map, centered on the north pole. The map is surrounded by an

olive(橄榄)wreath(花环)symbolizing peace and co-operation. The flag is blue and white.

1. Flags have been in existence for ____    

A.500 years

B. more than 3000 years

C. about 2000 years

D. between 500 and 2000 years

2. A very old flag is likely to _____.

A. be made of fabric

B. have a map on it

C. have white shapes on it

D. be made of carved wood

3. An olive wreath is used to represent_______ .

A. peace

B. purity    

C. justice

D. equality

下列关于聘用员工的描述中错误的是（）。

A.企业可以与员工通过私下协商不与员工签订劳动合同

B.涉及到知识产权、国家秘密的员工，企业要与其签订保密协议，要求其履行员工的保密义务

C.企业选聘人员应当实行岗位回避制度

D.银行应当建立选聘人员试用期和岗前培训制度

盐渍保存法中食盐用量应当有效的控制在（）

A、1%-5%

B、5%-10%

C、10%-20%

D、20%-30%