题干
They finished their meal in silence.
A：with great noise
B：without saying anything
C：quickly
答案(点此获取答案解析）
B
They finished their meal in silence.
A：with great noise
B：without saying anything
C：quickly
的固定光滑斜面下滑时（如下左图所示），滑块对斜面的压力大小为F1；另一同样的滑块放在另一个同样光滑的斜面上，在外力F推动下，滑块与斜面恰好保持相对静止共同向右加速运动（如下右图所示），这时滑块对斜面的压力大小为F2。则F1：F2等于（ ）