I went to school without ____ (eat) anything this morning.
We ____ ____ to see our teacher next week.
在一个竖直方向运动的密闭升降机内,用弹簧秤挂着一个已知质量的砝码,当地的重力加速度已知.根据弹簧秤的读数,我们可以知道( )
求证:DE是⊙O的切线.