封头冲压胎膜的下胎设计成拉环结构,当采用压边装置时,下胎圆角半径为()mm。(其中S为封头壁厚)
A.(3~6)S
B.(3~4)S
C.(2~3)S
D.(1~2)S
参考答案:C
-I have no paper _________. Could you lend me some?
-OK, here you are. [ ]
A. to write
B. to write with
C. writing on
D. to write on
如图所示电路中,电源电动势为6V,内电阻为14个电阻均为3.(1)若在a、b两点间接上理想电压表,则读数多大?(2)若在a、b两点间接上理想电流表,则读数多大?