如图所示，以9.8 m/s的水平初速度v₀抛出的物体，飞行一段时间后，垂直地撞在倾角θ为30°的斜面上。可知物体完成这段飞行的时间是

A．

B．

C．

D．2 s

Our English teacher devoted herself____ to her teaching and it earned her a good

    reputation in our school．

A．strongly

B．extremely

C．entirely

D．freely