Keep the windows ____ (open), please. It's a little hot in the room.
甲、乙两种物质的质量和体积关系如图所示,如分别用甲、乙两种物质制成体积相等的两实心物体a和b,放在水中静止后,则( )
实验中,电流表(0.6A量程)、电压表(3V量程)的某组示数如图所示,图示中I=____A,U=____V.