根据现有相关法律、行政法规的规定,上市公司的财务会计报告,必须经过注册会计师审计才能对外提供。 ( )
参考答案:对
某同学将量程为200μA、内阻为500Ω的表头μA改装成量程为1mA和10mA的双量程电流表,设计电路如图(a)所示.定值电阻R1=500Ω,R2和R3的值待定,S为单刀双掷开关,A、B为接线柱.回答下列问题:
(1)按图(a)在图(b)中将实物连线;
(2)表笔a的颜色为______色(填“红”或“黑”)
(3)将开关S置于“1”挡时,量程为______mA;
(4)定值电阻的阻值R2=______Ω,R3=______Ω.(结果取3位有效数字)
(5)利用改装的电流表进行某次测量时,S置于“2”挡,表头指示如图(c)所示,则所测量电流的值为______mA.
There _____ a lot of coal mines in the south, but many of them have been closed or are _____ be closed.
A.use to having; about to
B.used to be; to
C.use to having; going to
D.used to be; supposed to