在不断变化的环境中,我们需要随时调整自己的行为,以____变化的环境。
A father in the UK has a wonderful idea to send his kids to school on time. He takes his sons to school in a white tank(坦克).
如图,在M、N处固定两个等量同种点电荷,两电荷均带正电.O点是MN连线的中点,直线PQ是MN的中垂线.现有一带正电的试探电荷q自O点以大小是v0的初速度沿直线向Q点运动.若试探电荷q只受M、N处两电荷的电场力作用,则下列说法正确的是( )