如图所示是小明自制的水平仪,它由两条相互垂直的木条加上一根重垂线组成,用它能检查桌面是否水平,该水平仪利用重力方向____ 的原理.
A:I called you yesterday. You didn't answer it. B:Oh, sorry. I_ in the bathroom at that time.
下列产品中属于日本生产的是( )