—I want to go out for a dinner. Is there a _________ near here? —Yes, there is one across from the post office.
A:bookstore
B:supermarket
C:museum
D: restaurant
如图,两根足够长光滑平行金属导轨PP′、QQ′倾斜放置,匀强磁场垂直于导轨平面,导轨的上端与水平放置的两金属板M、N相连,板间距离足够大,板间有一带电微粒,金属棒ab水平跨放在导轨上,下滑过程中与导轨接触良好.现同时由静止释放带电微粒和金属棒ab,则( )
下列说法中,完全正确的是 ( )