公共汽车在平直的公路上匀速行驶,站在车里的人在水平方向上( )
|
| A. | 受到向前的摩擦力 | B. | 受到向后的摩擦力 |
|
| C. | 受到汽车对它的牵引力 | D. | 不受力 |
[单选题]Normal 0 7.8 磅 0 2 false false false MicrosoftInternetExplorer4 1.根据系统安全工程的观点,危险是指系统中存在发生不期望后聚的可能性超过了人们的承受程度。一般用危险度来表示危险的程度。在安全生产管理中,危险度通常由( )决定。A.事故发生的可能性和事故的类别B.事故严重性和影响范围C.事故发生的可能性和事故后果的严重性D.事故的严重性和事故发生后的应急救援能力
[单选题]若 Normal 0 7.8 磅 0 2 false false false EN-US ZH-CN X-NONE MicrosoftInternetExplorer4 y1·y2为二阶线性常系数微分方程y〞+p1y'+p2y=0的两个特解,则C1y1+C2y2().A.为所给方程的解,但不是通解B.为所给方程的解,但不一定是通解C.为所给方程的通解D.不为所给方程的解
[单选题]执行完下列代码段之后: bool x=true, y=false, z=false; x=x&&y‖z; y=x‖y&&z; z=!(x!=y)‖(y-z); 则x=false, y=false, Z=( )。A.trueB.falseC.不确定D.异常
[单选题](一)下表为某地区2008年的人口数。Normal 0 7.8 磅 0 2 false false false EN-US ZH-CN X-NONE MicrosoftInternetExplorer4年初(人)年末(人)0~1420 93221 18215~64160 636186 01065~10022 01428 159注1:0~14为少年儿童人口注2:65以上为老年人口请据此表计算回答以下问题:76.该地区2008年的平均人口为( )。A.67 860.7B.73 155.5C.78 4
[单选题]What is a FALSE statement concerning the line throwing appliance on a vessel ().A.A drill on its use must be held once every three monthsB.The actual firing is at the discretion of the MasterC.The auxiliary line must be of a light colorD.The auxiliar
[单选题]Is the following statement true or false?A. significant change in the ownership of an existing audit client is a factor which makes it appropriate for the auditor to review the terms of engagement.A.TrueB.False
执行下列Python程序,输出结果是什么?( )x=True y=False w=False z=True print(not((x and y)or(w
[单选题]A.ccording to the passage, false beards were worn by those who considered themselves to be ______.A. handsome and matureB. too young to have beardsC. aristocrats or fashionable dandiesD. royalty
[单选题]Which statement is FALSE concerning precautions during fueling operations?()A . All engines,motors,fans,etc. should be shut down when fuelingB . All windows,doors,hatches,etc. should be closedC . A fire extinguisher should be kept nearbyD . Fuel tank