能够把细胞中的有机物分解,同时释放能量供给细胞利用的结构是()
A.液泡
B.线粒体
C.叶绿体
D.细胞核
参考答案:B
A change request in a project has been rejected some weeks ago.Yesterday,the project manager found out that it nevertheless has been implemented by the team members,who knew of the change request,but not of the rejection.In order to avoid such a situation,rejected change requests are input to which process ?()
A.Schedule developmen
B.Scope verificatio
C.Monitor and control project wor
D.Information distributio
如图(甲)所示,理想变压器原副线圈的匝数比为10:1,b是原线圈的中心抽头,电压表和电流表均为理想电表,除R以外其余电阻不计。从某时刻开始单刀双掷开关掷向a,在原线圈两端加上如图(乙)所示交变电压,则下列说法中正确的是:( )
A.该交变电压瞬时值表达式为(V)
B.滑动变阻器触片向上移,电压表示数不变,电流表的示数变大
C.s时,电压表的读数为31. 1V
D.单刀双掷开关由a扳到b,电压表和电流表的示数都变大