计算：3x2y（﹣2xy）结果是[]
A．6x3y2B．﹣6x3y2C．﹣6x2yD．﹣6x2y2

张老师出门散步，出门时5点多一点，他看到手表上分针与时针的夹角恰好为110°．回来时接近6点，他又看了一下手表，发现此时分针与时针再次成110角．则张老师此次散步的时间是（）
A．40分钟B．30分钟C．50分钟D．非以上答案

AAgroupoffrogsweretravelingthroughtheforests,butunluckilytwoofthemfellintoahole.Theotherfrogstriedtohelpthem.Whentheysawhow51theholewas,theycriedtothetwofrogsthattheycouldnotbesaved.Thetwofrogsdidn"t52andtriedtheirbesttojumpupoutofthehole.Theotherfrogs53sayingthattheyweresuretodie.54,oneofthetwofr-ogs,whoheardwhattheotherfrogsweresaying,55.Thenhefelldownanddied.Theotherfrog,however,56tojumpashardashecould,andatlastmadeitout.Whenhe57,theotherfrogsasked,"Di-dn"tyouhearus？"Thefrog,whohadapoor58,explained,"Ithoughtyouwereencouragingmeallthetimid."Thestoryteachesusa59:Thereispower(力量)oflifeanddeathinthetongue.An60wordtothosewhoaredowncanhelpthemoutwhileadiscouragingwordcankillt-hem.51.
A.smallB.deepC.bigD.wide

若a、b互为相反数，c、d互为倒数，则9（a+b）101-8（cd）100=______．

4的算术平方根是【】。
A．2B．-2C．±2D．2

某火车站现有甲种货物1530吨，乙种货物1150吨，安排一列挂有
A、B两种不同规格的货厢50节的货车将这批货物运往广州．已知用一节A型货厢可用甲种货物35吨和乙种货物15吨装满，运费为0.5万元，用一节B型货厢可用甲种货物25吨和乙种货物35吨装满，运费为0.8万元．设运输这批货物的总费用为W万元，用A型货厢的节数是x节．（1）用x代数式表示W．（2）有几种运输方案．（3）采用哪种方案运费最少？最少运费是多少万元？