计算机的主存储器(内存)用来存储数据和指令，为了实现按地址访问，每个存储单元必须有一

The   Grade 3 students at the Clean City School collect empty bottles .In June ,they are going to take them to a recycling ()   center .They are going to sell the bottles and buy some books for  the school library.

Kate has started a graph (图表) to show the number of the bottles they have collected . This is the graph .

Student Bottle Collection

The months of the School Year

小题1:In October the students collected ______ empty bottles.

A．80

B．60

C．40

D．20小题2:The students collected  _____ more bottles in December than in January .

A．10

B．20

C．30

D．40小题3:Form  the graph above ,we know that the students picked up the same number of bottles in  ______ and  ______ .

A． October ;February

B．September ;April

C．January ;May

D．November ; March小题4:Why do the students collect empty bottles ? Because they ______ .

A．want to do something for their school

B．like empty bottles very much

C．want to play with the bottles

D．want to sell them to buy balls小题5:How many bottles have they collected in November?

A． 20

B．40

C．60

D．80

某宽厚板车间冷床区为三跨等高厂房，跨度为35m；边列柱柱间距为10m，中列柱柱间距为20m，局部60m；采用三跨连续式焊接工字形屋面梁，其间距为10m，屋面梁与钢柱为固接。厂房屋面采用彩色压型钢板，屋面波度为1/20；檩条采用多跨连续式H型檩条，其间距为5m；檩条与屋面梁搭接。屋面梁、檩条及屋面上弦水平支撑的局部布置示意如图16-25(乙)中的(a)图所示，且系杆仅与檩条相连。

中列柱柱顶设置有20m和60m跨度的托架，托架与钢柱采用铰接连接，托架的简图和荷载设计值如图16-25(乙)中的(b)和(c)图所示。屋面梁支承在托架竖杆的侧面，且屋面梁的顶面略高于托架顶面约150mm。

檩条、屋面梁、20m跨度托架采用Q235B钢，60m跨度托架采用Q345B钢。手工焊接时，分别采用E43型焊条和E50型焊条，要求焊缝质量等级为二级。

20m跨度托架杆件采用轧制T型钢，T型钢的翼缘板与托架平面想垂直。60m跨度托架杆件采用轧制H型钢，H型钢的腹板与托架平面相垂直。

60m跨度托架腹杆V₂的轴心压力设计值N=1855kN，拟采用热轧H型钢H390×300×10×16。i_x=169mm，i_y=72.6mm，A=13670m㎡。当按轴心受压构件进行稳定性计算时，杆件的最大应压力(N/m㎡)与下列何项数值最为接近 （）

A.162

B.194

C.253

D.303

基因转录活跃的染色质区段的结构特点是（）

A.紧密包装为核小体

B.以常染色质形式分散在核内

C.以异染色质形式分散在核周

D.组蛋白结合率较高

E.对DNA酶有抵抗能力

依据《煤矿安全监察条例》和《煤矿安全监察员管理暂行办法》的规定，煤矿安全监察员在检查中发现影响煤矿安全的违法行为，有权( )。

A．要求立即停止作业
B．当场予以纠正或者要求限期改正
C．立即责令纠正或者责令立即停止作业
D．予以罚款或者警告

哈耶克